35 Such action on the part of individual Christians, then, along with the ascetic effort promoting them to purify their hearts, actually stimulates in the faithful those energies which enable them to participate in the august sacrifice of the altar with better dispositions. They now can receive the sacraments with more abundant fruit, and come from the celebration of the sacred rites more eager, more firmly resolved to pray and deny themselves like Christians, to answer the inspirations and invitation of divine grace and to imitate daily more closely the virtues of our Redeemer. And all of this not simply for their own advantage, but for that of the whole Church, where whatever good is accomplished proceeds from the power of her Head and redounds to the advancement of all her members.
Source: Mediator Dei (Vatican.va)