Having done enough, then, as we have said, in regard to that principal argument, that there is in them all the taint of idolatry— having sufficiently dealt with that, let us now contrast the other characteristics of the show with the things of God. God has enjoined us to deal calmly, gently, quietly, and peacefully with the Holy Spirit, because these things are alone in keeping with the goodness of His nature, with His tenderness and sensitiveness, and not to vex Him with rage, ill-nature, anger, or grief.
Well, how shall this be made to accord with the shows? For the show always leads to spiritual agitation, since where there is pleasure, there is keenness of feeling giving pleasure its zest; and where there is keenness of feeling, there is rivalry giving in turn its zest to that. Then, too, where you have rivalry, you have rage, bitterness, wrath and grief, with all bad things which flow from them— the whole entirely out of keeping with the religion of Christ. For even suppose one should enjoy the shows in a moderate way, as befits his rank, age or nature, still he is not undisturbed in mind, without some unuttered movings of the inner man.
No one partakes of pleasures such as these without their strong excitements; no one comes under their excitements without their natural lapses. These lapses, again, create passionate desire. If there is no desire, there is no pleasure, and he is chargeable with trifling who goes where nothing is gotten; in my view, even that is foreign to us. Moreover, a man pronounces his own condemnation in the very act of taking his place among those with whom, by his disinclination to be like them, he confesses he has no sympathy.
It is not enough that we do no such things ourselves, unless we break all connection also with those who do. “If you saw a thief,” says the Scripture, “you consented with him.” Would that we did not even inhabit the same world with these wicked men! But though that wish cannot be realized, yet even now we are separate from them in what is of the world; for the world is God's, but the worldly is the devil's.
Source: De Spectaculis (The Shows) (New Advent)