What are the spiritual works of mercy?
The spiritual works of mercy are traditionally listed as:
By exhortation, to convert the sinner from the error of his way, the greatest of rescues: “whoever brings back a sinner from wandering will save a soul from death and will cover a multitude of sins” (Jas 5:19–20), always “in a spirit of gentleness,” looking to ourselves, lest we too be tempted (Gal 6:1);
To instruct the ignorant in truth and virtue, the very work of catechesis, whose reward the prophet Daniel foresaw: “those who are wise shall shine like the brightness of the firmament; and those who turn many to righteousness, like the stars for ever and ever” (Dan 12:3; cf. 2Ti 2:24–25; see Q382, Q383);
To give our neighbor good and timely counsel in difficulty or unseen danger, for “oil and perfume make the heart glad, and the sweetness of a friend comes from his earnest counsel” (Prv 27:9), and “where there is no guidance, a people falls; but in an abundance of counselors there is safety” (Prv 11:14);
To pray for others to God, “first of all, petitions, prayers, intercessions and thanksgivings be made for all: for kings and all in high places” (1Ti 2:1; see Q266, Q376); “pray for one another so that you may be healed” (Jas 5:16; see Q264, Q266), a duty so binding that Samuel counted its neglect a sin: “far be it from me that I should sin against the LORD by ceasing to pray for you” (1Sa 12:23; see the Study: Prayer, Intercession, and the Divine Council);
To comfort the afflicted, “encourage the fainthearted, support the weak, be patient toward all” (1Th 5:14; see Q578a), passing on “the comfort with which we ourselves are comforted by God” (2Co 1:4); remembering that comfort sometimes means simply staying near, as Job’s friends did best when they sat with him in silence (Job 2:13);
Not to return the evil that others have done to us, “repay no one evil for evil… do not be overcome by evil, but overcome evil with good” (Rom 12:17, 21); “do not return evil for evil or reviling for reviling, but on the contrary bless: for to this you have been called, that you may obtain a blessing” (1Pe 3:9);
To forgive injuries from the heart, not with the lips only, for the Lord concludes his parable of the unforgiving servant: “This is how my heavenly Father will also treat you if you do not each forgive each other their trespasses from your hearts” (Mat 18:35); “be kind to one another, tenderhearted, forgiving each other just as God also forgave us in Christ” (Eph 4:32).