Advice on works of mercy from the angelic doctor:
106. Here I think of Saint Thomas Aquinas, who asked which actions of ours are noblest, which external works best show our love for God. Thomas answered unhesitatingly that they are the works of mercy towards our neighbor, [Cf. Summa Theologiae, II-II, q. 30, a. 4] even more than our acts of worship: “We worship God by outward sacrifices and gifts, not for his own benefit, but for that of ourselves and our neighbor. For he does not need our sacrifices, but wishes them to be offered to him, in order to stir our devotion and to profit our neighbor. Hence mercy, whereby we supply others’ defects, is a sacrifice more acceptable to him, as conducing more directly to our neighbor’s well-being”. [Ibid., ad 1]
Unlike human assessment of pagan gods, Christians and Jews know deep down they serve a selfless Divinity, a God who is concerned for all creation, not the Divine Self and not the “special ones” who find their lives a blessings. It’s a potent remedy for gnosticism. And it keeps the focus off the self, lest we become tempted to be our own petty god.
You can check the full document Gaudete et Exsultate on the Vatican website.