I'd like to focus on the notion of the kingdom of God, which is so prominent in the New Testament. It is such an important notion, but it is rather difficult because it is so multifaceted. The kingdom of God is at the heart of Christ's preaching.
Now after John was arrested, Jesus came into Galilee, preaching the gospel of God, and saying, "The time is fulfilled, and the kingdom of God is at hand; repent, and believe in the gospel." (Mk 1, 14-15)
Jesus speaks specifically of the good news of the kingdom of God (Lk 4, 43). I've often asked my students in the past: "You have had about 10 years of Catholic education, and you've heard the words "good news", and of course the word 'gospel' means good news. Tell me: what is the good news?" More often than not, they simply have no clue. I once met a Catholic nun in the U.S who was beginning to buy into the latest ideological fads, political in nature, that are typically nothing more than temporary substitutes for the authentic kerygma of the Church, and as I was arguing with her, it became rather obvious that she seemed to me to lack a basic understanding of the faith. So at one point I asked her: "What is the good news of the gospel?" She too was stuck for an answer, which is why over the years I have wondered whether or not she is still a Catholic nun. I say this to stress the point that political ideologies are not the gospel. Christ was not a political revolutionary; he did not speak of "social justice" - which is not to suggest that Christ's teaching and his life have no social implications, they certainly do, but the cart must never be placed before the horse. Christ came to proclaim the good news; he came to establish it. He is the good news.
The good news is the establishment of the kingdom of God in him. But what does that mean exactly? Certainly this is strange language to modern ears; for we don't speak of kingdoms, but provinces, nations, countries, and we speak of Prime Ministers and Presidents, not kings. So what does this really mean?
Consider this historically. Under king David, the nation of Israel became a kingdom that subjugates other nations. In fact, at the time of Christ, the Jews were expecting a Messiah who would restore Israel to its former status as a kingdom. They were expecting a Messiah like David, a soldier who would lead the defeat of the Romans and free Israel from Roman occupation. But that is not the kingdom Jesus came to establish. He said to Pilate: "My kingdom is not of this world" (Jn 18, 36). And in the synoptic gospels, Jesus foretells his passion three times. The reason is that he is preparing his followers so that they may come to understand his true mission. He came to defeat another enemy, the one enemy that man cannot defeat; for he came to conquer sin and its offspring, which is death. The good news of the gospel is the resurrection. And if death has been conquered, sin has been conquered, because death is the effect of sin; for death entered into the world as a result of the sin of the first parents of the human race.
But 'good news' (gospel) and 'kingdom of God' are often used together in the New Testament. A king governs a kingdom, and a kingdom is an empire that subjugates other nations. Christ came to establish the kingdom of God over and against the kingdom of darkness. The kingdom of darkness is a different kingdom. Recall the story of Genesis: "God said 'Let there be light', and God separated the light from the darkness". This is the creation of the angelic realm. Angels are immaterial, pure spirits, created intellectual lights, and so they are not limited by matter and subject to time as material things are, such as human persons, who are composites of spirit and matter. And angels choose instantaneously whether to serve God or rebel against God. And so, immediately after God created the light of the angelic spirits, God separated light from darkness, that is, He separated the good angels from the rebellious, the angels of darkness. And we know from a study of the fall of man in Genesis chapter 3 that the devil, the prince of darkness, draws the first parents of the human race into the current of his own rebellion. Through his inspiration, darkness enters into the world. The result of the first sin is death, concupiscence, and a loss of the life of grace and the sense of the divine. Sin and darkness spread throughout the world as history continues.
Moving right into the New Testament to the biblical story of the temptation in the wilderness, the devil tempts Jesus in the desert. In the second temptation in the gospel of Luke, we read: "Then the Devil took him up and showed him all the kingdoms of the world in a single instant. The devil said to him, "I shall give to you all this power and their glory; for it has been handed over to me, and I may give it to whomever I wish. All this will be yours, if you worship me." Jesus said to him in reply, "It is written: 'You shall worship the Lord, your God, and him alone shall you serve.'" Notice what the devil says: "...the kingdoms of the world have been handed over to me, and I may give it to whomever I wish". And in the first chapter of the gospel of John, we read that the light entered the darkness. Jesus came to free man from the kingdom of darkness. He came to defeat that kingdom, to take back what rightfully belongs to God, to free man from the dominion of Satan. In the first letter of John, we read: "Indeed, the Son of God was revealed to destroy the works of the devil."
Christ came to buy back (redeem) the human race, to deliver man from the darkness of this kingdom. And so a battle ensues. This temptation in the wilderness is the first round of this battle, and the first round goes to Christ. This kingdom, the kingdom of darkness, is both a visible and an invisible kingdom. Its origin is invisible (the demonic realm); its effects are visible in human sinfulness manifest in history. This is a kingdom that was established in the beginning, not at a particular time in history, as was the Roman or Alexandrian empires. When the first parents cooperated with the evil one and chose to taste radical independence from God, for themselves and their offspring, they submitted themselves to him. They rejected their status as children dependent upon God. Christ came to undo the work of the evil one, and the work of the evil one was to draw humanity into his own sin and rebellion, with all its effects. Christ came to reverse that.
But how is Christ going to reverse that? He reverses that in his Incarnation, death, and resurrection. By his Incarnation, the Second Person of the Trinity joins his divinity to our humanity. The Son dwells among us. The signs of the impending defeat of the kingdom of darkness occur almost immediately, beginning with the overcoming of temptation in the desert, but they continue in the miracles Christ worked, in his miracles over nature (changing water into wine, the calming of the storm, etc.), in the raising of a 12 year old girl from the dead and the raising of Lazarus, which imply his power over death, and most importantly in his forgiving others of their sins, something only God can do. All these are signs that the kingdom of God is among us.
When Jesus returned to Capernaum after some days, it became known that he was at home. Many gathered together so that there was no longer room for them, not even around the door, and he preached the word to them. They came bringing to him a paralytic carried by four men. Unable to get near Jesus because of the crowd, they opened up the roof above him. After they had broken through, they let down the mat on which the paralytic was lying. When Jesus saw their faith, he said to the paralytic, "Child, your sins are forgiven."
Now some of the scribes were sitting there asking themselves, "Why does this man speak that way? He is blaspheming. Who but God alone can forgive sins?" Jesus immediately knew in his mind what they were thinking to themselves, so he said, "Why are you thinking such things in your hearts? Which is easier, to say to the paralytic, 'Your sins are forgiven,' or to say, 'Rise, pick up your mat and walk'? But that you may know that the Son of Man has authority to forgive sins on earth", he said to the paralytic, "I say to you, rise, pick up your mat, and go home." He rose, picked up his mat at once, and went away in the sight of everyone. They were all astounded and glorified God, saying, "We have never seen anything like this." (Mk 2, 1-12)
Christ, who is Messiah, exercises power over the kingdom of darkness; he forgives sins and cures the sick. Rise up, he says, just as he will say to Lazarus and the 12 year old girl whom he raised from the dead. Christ exercises dominion over death. But his definitive defeat of this kingdom takes place on Good Friday. By dying, he destroys death, by rising, he restores life. His blood is the price he paid for the sins of man, and the proof that they have been forgiven is his resurrection, for sin begets death, but divine grace begets life.
So what is this kingdom of God? The kingdom of God is something that cannot be adequately expressed in one answer, which is why we have a multitude of parables of the kingdom. Each one highlights one aspect of that kingdom. What we can say is that it is not of this world. Indeed, it is in this world, but it is not of this world. It is not a political kingdom. And like the kingdom of darkness, it is both visible and invisible. Its origin is invisible; its sustaining source is invisible - the Holy Spirit is invisible. But it is visible insofar as Christ is visible, and insofar as the kingdom has a grip on visible human beings, in particular the visible Church that Christ established on the twelve foundation stones of the Apostles. And, it is a kingdom that grows and develops in history. Consider the parable of the mustard seed:
He proposed another parable to them. "The kingdom of heaven is like a mustard seed that a person took and sowed in a field. It is the smallest of all the seeds, yet when full-grown it is the largest of plants. It becomes a large bush, and the 'birds of the sky come and dwell in its branches.'" (Mt 13, 31-32)
A very short parable, but it conveys only an aspect of that kingdom, namely, its developmental nature: the kingdom of God develops and evolves in history; it begins small, but grows, develops in time, within history.
The kingdom of God is an invisible kingdom that is here, within the confines of space and time, developing like a plant. The kingdom of God is the redemptive presence of God through the power of the reconciling Spirit . Christ said that he has overcome the world. Christ redeemed us. His presence, his influence, his life, his grace, is in the world. It has been joined to matter. The divine life, divine grace, is intimately present to a sufficient degree to each individual person, and it is up to each person to accept that grace or reject it. Those who accept his grace and cooperate with it will possess sanctifying grace, which is a supernatural quality that is indwelling and habitual, unlike sufficient grace. To be in a state of sanctifying grace does not mean one has achieved spiritual perfection. Rather, it means that one has freely opened himself to the divine nature, which now dwells within; for grace is a sharing in the divine life. This makes one a member of Christ's Mystical Body, for the Holy Spirit descended upon the Apostles on Pentecost. The Holy Spirit is the very soul of the Church. Hence, the kingdom of God is present in the world, through that Mystical Body.
The king, who is Christ, is the king of the universe, but he does not reign by force. He does not compel. First and foremost, he reigns within; he reigns through the free cooperation of human persons, and so Christ reigns in his Church. But he does not yet reign in the world of which he is king. Not yet. The world will not allow him to. There is still darkness, enmity, strife, war, between the offspring of the evil one and the offspring of the woman (Gn 3, 15). And so we see history as a battle. We are at war. You are at war. It is not a war fought with conventional weaponry. It is a spiritual battle. My spiritual director would always remind teachers: "There is a war for the souls of our students". And our responsibility as teachers is to enter into this battle and go to war for them, for their sake, to protect them from the subtle influence of darkness. And that means coming to know that faith, and above all witnessing to the joy of Christ's resurrection, the joy of belonging to that kingdom, being under the influence of that kingdom, allowing that kingdom, that redemptive presence, to have dominion over your own life; it involves praying for our students, helping them to see the world through the eyes of faith. It is a highly dignified vocation. A very noble one. It's no longer completely in the hands of the clergy, the religious, as it was of old, when the schools were run by the religious orders. Now, it is up to you and me to carry on that mission, to enter into that battle.
So, even now, Christ is still in the process of defeating his enemies, but he defeats his enemies in the same way that he did when he came among us 2000 years ago in Palestine: as a servant, a humble servant, through the power of the cross. He does not come in military and political power, as did the kings of history. He defeats the kingdom of darkness in "weakness", for "the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength" (1 Co 1, 25). God is so powerful that he defeated the one enemy that man could not defeat, namely sin and death, and he did so by dying on a cross. The eternal Person of the Son, who is Life and Light, allowed himself to be swallowed up in death, like a mound of earth would swallow up a stick of dynamite, only to be detonated. Christ's life fills the darkness of death with the light of life. For the rest of us, dying is loss, it is defeat, but for God, dying is victory. And our dying becomes light and victory in him.
And so the crucifix has become the most powerful sign under which we operate - that is why it is so important to have a crucifix in every room of our house, especially in each classroom, and not the resurrected figures fixed to a cross, but a crucifix; Satan recoils from the crucifix, because it is the sign of his definitive defeat.
Another parable of the kingdom that illustrates an aspect of the kingdom is the following:
"The kingdom of heaven is like yeast that a woman took and mixed with three measures of wheat flour until the whole batch was leavened." (Mt 13, 33)
Yeast takes time to influence the entire loaf. The kingdom of God is in the world like yeast. A teacher is above all yeast, and a good teacher has influence. That's the power of a teacher. Influence. It is a real tragedy to have a teacher spend over 30 years in the classroom, with a mission to witness to the good news of the kingdom, to inspire kids to enter that world of grace, truth, and joy, and to neglect that mission completely, to waste those years, by seeing his teaching profession merely as a job, to become totally preoccupied with making his life easier, doing as little as possible. The light that they could have brought into the classroom but did not, because their faith was lifeless, limp, unenlightened and ineffective. Such teachers are forgettable, for instead of bringing light into the classroom, they bring tension, darkness, and hardness.
It is the faith of the Church that it is impossible for man, outside of Christ, to establish peace and justice on earth. Man is inclined to sin. In the Psalms we read: "Unless the Lord builds the house, in vain to the builders labor" (Ps 127, 1). The fullness of the kingdom will only be achieved in the Second Coming of Christ, the Parousia. What we do in the meantime is allow Christ the King to reign in our own lives, and we influence people that way. When Christ the King reigns in our lives, we begin to love with the heart of Christ. We love with humility. We love with the love that we see from the cross, which is a love the world cannot understand, because the world only understands power and politics. It does not understand the humility of the divine love. The world admires strength, wealth, fame, youthfulness, etc. But God the Father admires His Son, who:
...though he was in the form of God, did not regard equality with God something to be grasped. Rather, he emptied himself, taking the form of a slave, coming in human likeness; and found human in appearance, he humbled himself, becoming obedient to death, even death on a cross. Because of this, God highly exalted him and bestowed on him the name that is above every name, that at the name of Jesus every knee should bend, of those in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. (Phil 2, 6-11)
The kingdom of God, as we said above, is an invisible kingdom, but it is visible insofar as it dwells within the hearts of visible sinful, flawed, neurotic human beings who make up Christ's Mystical Body, the Church. Christ the king reigns in his Church, and Christ reigns in the hearts of our Protestant brethren who speak and act in his name, and he also reigns implicitly and perhaps pre-consciously in many of our Muslim, Hindu, Sikh, etc., brothers and sisters of good will, who are open to divine grace, whose decisions are moved by divine grace, even without them knowing it explicitly. These are part of the invisible Church.
There will always be conflict between the two kingdoms. We know this from the words of Christ himself who said: "If the world hates me, know that it will hate you too" (Jn 15, 18). We also know this from as far back as the book of Genesis: "I shall put enmity between you and the woman, between your offspring and hers. She will crush your head, while you will bite at her heel" (3, 15). The woman is Israel, as well as the New Israel, Christ's Mystical Body, the Church, and the Blessed Mother, whose offspring is Jesus. That battle plays out in history, and we are part of it. The specific task assigned to us is to bring the light of the gospel, the commands of Christ, and the message of Christ's forgiveness of sins to the students entrusted to us. We labor for the next 30 years or so, but in the end, the Lord will take our labors, all our works of charity, as a builder takes wood, glass, and steel, and he will make the final product. But he will usher in the fullness of the kingdom, and when that will occur, no one knows. In large part it does depend on us in that we create the conditions for his ushering in the fullness of that kingdom; we delay that coming or we hasten it by our cooperation or lack of cooperation. Moreover, eternal life with God in the fullness of the kingdom will include the resurrection of the body, our bodies, for we profess this in the Creed, and it will include the Beatific Vision, which is the vision of God as He is in Himself. To see God as He is in Himself is to possess the Supreme Good, the source of all that is Good. Everything you and I desire in this life is ultimately a desire for God, for everything we desire in this life is only a finite good which does not satisfy indefinitely, but only temporarily. The human heart was created by God and for God, and in the human heart is an infinite thirst, and only one thing in reality is infinite, and that is God Himself. The happiness of the eternal possession of God (heaven) is unimaginable. It is not in any way comparable to a Club Med vacation. Any depiction of heaven in film or media is necessarily false, for it is beyond our ability to conceive. However, the more you grow in prayer and begin to experience the joy of intimacy with God and grow in a deeper sense of the divine, you will begin to get glimpses of what the happiness of heaven really is and what it is not; for this is a very subtle joy that is indescribable.
But the joy of heaven begins now, in this life. Christ said that "the kingdom of God is within you". Too often, Catholic teachers speak as if our mission is to build a utopia, that the kingdom of God is some sort of utopian society that we create, and so the gospel is once again reduced to politics, and what happens then is that political action takes priority, rather than the personal action of the pursuit of holiness, through prayer, confession, Eucharist, works of charity, etc., and soon the teaching of religion becomes a matter of encouraging students to political activism. The fact is social justice will naturally proceed from a life that is growing in holiness.
St. Paul tells us that you are the temple of the Holy Spirit, and so each one of us is called to be a sacred space, a temple that houses the presence of God. The light that will fill that temple if we are open will certainly illuminate our own life, our own interior, but as teachers, that light will illuminate the space outside of us so that others can begin to make their way through the darkness. That is the great blessing of the vocation of a Catholic teacher. The greatest joy in store for those who have sought first the kingdom of God and left all else to God's providence will be the awareness that they've loved God far more than they thought they did and that the Lord has accomplished so much more, through their efforts, labors and sufferings, than they could have possibly imagined.