I have this difficulty with "cheap forgiveness", a mainstay of the culture. Christians are not immune.
So I am providing some background on "forgiveness", something we are bound to do, but something that has suffered at the hands of the "therapeutic culture," where it has somehow morphed to become a variant of that "unconditional love" shibboleth that is always tossed out as a justification for sin.
In point of fact, while we are commanded by God to forgive, we are not commanded to be more forgiving than God, who is the penultimate "judgmental" Being who made us all, and stands ever ready to forgive us our sins if we repent and approach Him with (perfect or imperfect) contrition.
I will acknowledge that the therapeutic culture is right in on one respect. It frees the soul not to nurse anger over injury; however, there is nothing new in this (see the Trent Catechism entry below). On the other hand, the willingness to forgive, and ability to forget injury, are not the same as forgiving the one who did injury. We are asked to "be perfect, as our heavenly Father is perfect", and in this we are to stand ready to forgive. But we can no more forgive the unrepentant that God will forgive us if we are unrepentant.
It is true, we can and should with all charity pray to God and ask Him to forgive others, as Jesus, St Stephen, Moses, and Job did. But you will note: Jesus on the cross said "Father, forgive them, they know not what they do." He did not forgive them, as he did so many other times ("go, your sins are forgiven"). In the material that follows, you will find exhortation to make intercessory prayer for those who have injured you.
What follows is, I hope, what might be a counter-cultural primer on forgiveness. It contains entries from the Catechism of Trent (used for the remarkable clarity), Scripture, St Augustine, and Denzinger.
Innumerable are the evils brought upon man by sin, that almost infinite pest of which David says: There is no health in my flesh, because of thy wrath; there is no peace for my bones, because of my sins. In these words he marks the violence of the plague, confessing that it left no part of him uninfected by pestiferous sin; for the poison had penetrated into his bones, that is, it infected his understanding and will, which are the two most intimate faculties of the soul. This widespread pestilence the Sacred Scriptures point out, when they designate sinners as the lame, the deaf, the dumb, the blind, the paralyzed.
How great is the utility of this sort of instruction, which teaches us to grieve for our sins, God Himself declares by the mouth of Jeremias, who, when exhorting the Israelites to repentance, admonished them to awake to a sense of the evils that follow upon sin. See, he says, that it is an evil and a bitter thing for thee, to have left the Lord thy God, and that my fear is not with thee, saith the Lord, the God of hosts. They who lack this necessary sense of acknowledgment and grief, are said by the Prophets Isaias, Ezechiel and Zachary to have a hard heart, a stony heart, a heart of adamant, for, like stone, they are softened by no sorrow, having no sense of life, that is, of the salutary recognition (of their sinfulness).
As is declared in an Article of the Creed, Christ the Lord has given power to the Church to remit sins.