Scripture explores the believer’s response to God’s grace.
56. Only on the basis of God’s gift, freely accepted and humbly received, can we cooperate by our own efforts in our progressive transformation.*
* This is, in a word, the Catholic doctrine on “merit” subsequent to justification: it has to do with the cooperation of the justified for growth in the life of grace (cf. Catechism of the Catholic Church, 2010). Yet this cooperation in no way makes justification itself or friendship with God the object of human merit.
So, let’s be careful. The believer’s relationship with God involves movement on both sides. God’s agency always comes first. Once God initiates, the question is: how do we respond?
We must first belong to God, offering ourselves to him who was there first, and entrusting to him our abilities, our efforts, our struggle against evil and our creativity, so that his free gift may grow and develop within us: “I appeal to you, therefore, brethren, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God” (Rom 12:1). For that matter, the Church has always taught that charity alone makes growth in the life of grace possible, for “if I do not have love, I am nothing” (1 Cor 13:2).
You can check the full document Gaudete et Exsultate on the Vatican website.
Catholic Sensibility 