"Why do we have to go to Mass?" is one of the most frequently asked questions that students address to their religion teachers, and recently I received an email from a former student asking for an article that he could share with his friends that answers that very question.
There is obviously a scriptural basis for going to Mass, but there is also a basis in human reason. The human person is the subject of a host of duties. It is the virtue of justice that dictates how he ought to respond to those duties. Firstly, he has a duty towards his equals: a duty to pay back what he borrowed, to tell the truth, a duty not to kill, etc. But he also has debts that he cannot fully repay, but which he is required to try to repay to the fullest extent possible. For example, we have a debt to the social whole, for we have benefited from the generosity of countless others in ways that we cannot fully appreciate. It is the virtue of natural piety that inclines a person, in gratitude, to render due honor and service to the country as a whole. We have a debt to our parents that cannot be fully remitted, and it is again the virtue of filial piety that inclines us to render due honor and worship to them. But above all, we have a debt to God that cannot be fully repaid. Everything we have been given, every blessing and every human good that we enjoy comes ultimately from God, the First Cause of all that is. It is the virtue of religion, the most perfect part of the virtue of justice, that seeks to render due honor and worship to God within the same spirit of gratitude. And so it is reasonable, a requirement of justice in fact, to be religious. One is not entirely just if one is not religious.
For a Catholic, though, that's half the story. There are more weighty reasons that are offered by divine revelation. Christ came to save us. He came to save us from sin and the prospect of eternal death. He came ultimately to die for us: "There is a baptism with which I must be baptized, and how great is my anguish until it is accomplished!" (Lk 12, 50). It is his death and resurrection that saves us. He alone could buy us back from unending death by offering his life as a ransom because he alone is divine, that is, fully God and fully man. His sacrifice on the cross is the perfect act of religion offered on our behalf, and it is this act that justifies us, redeems us, and saves us: "Indeed, only with difficulty does one die for a just person, though perhaps for a good person one might even find courage to die. But God proves his love for us in that while we were still sinners Christ died for us. How much more then, since we are now justified by his blood, will we be saved through him from the wrath. Indeed, if, while we were enemies, we were reconciled to God through the death of his Son, how much more, once reconciled, will we be saved by his life" (Rm 5, 7-10).
And so the question now is: "Why would someone not want to go to Mass?" In fact, why would a person not want to get to Mass every day?
But this perfect act of religion, offered once two thousand years ago, is perpetuated until the end of time. It is re-presented (made present) at every Mass. The Mass is a sacrifice, the same sacrifice offered on Calvary. This sacrificial act is opened up for us in order that we might enter into it, if we so choose. Christ, the eternal Son, has made his perfect offering to God the Father into real food and drink: "Whoever eats my flesh and drinks my blood has eternal life, and I will raise him on the last day. For my flesh is true food, and my blood is true drink. Whoever eats my flesh and drinks my blood remains in me and I in him" (Jn 6, 54-56). The Eucharist is literally Christ's body and blood. A priest is one who has been given the power to change ordinary bread and wine into Christ's body and blood. He alone can say Mass, thus making it possible for us to enter into the mystery of Good Friday. And it was Christ who said: "Do this in remembrance of me" (Lk 22, 19).
To sum this up, we have a natural duty to worship God in some visible way that expresses a real internal act of devotion. And this natural obligation of justice is further confirmed in the first three commandments of the Decalogue: "You shall have no other gods besides me; You shall not take the Lord your God's name in vain; Keep holy the Sabbath day" (Ex 20, 1-8). And finally, on top of all this, Christ gives us his very self in the Eucharist, allowing us to be part of the most perfect act of justice that alone brings eternal life, and from which we derive tremendous strength and the grace to do His will and achieve our destiny, which is to know and love Him for ever.
And so the question now is: "Why would someone not want to go to Mass?" In fact, why would a person not want to get to Mass every day? If we believe that Christ is really and truly present in the Eucharist, then it is not going to matter that the singing is bad or the sermon is boring. What will matter above all is that we receive communion. There is no greater privilege than that of being able to participate at an ordinary Mass and receive the body, blood, soul and divinity of Jesus Christ in the Eucharist. Such a privilege only adds to the debt we already owe to God, and since an element of our own happiness is the feeling of having a debt that cannot be paid, the more we grow to love the Mass and hunger for the Eucharist, the happier we will become.