your Lord, and to a Garden as wide as the heavens and the earth, prepared for the God-fearing—those who spend in ease and hardship, who suppress their anger and pardon people; and Allah loves the doers of good” (Āl ʿImrān 3:133–134).
“Those who suppress their anger” refers to people who, when provoked, restrain themselves, swallow their rage, and do not let that anger drive them to harm anyone.
“And who pardon people” means they forgive those who have wronged them. “And Allah loves the doers of good,” for forgiving the one who wrongs you is among the finest acts of goodness. Still, pardon has its proper place: if the offender is worthy of forgiveness, then forgiving him is praiseworthy; if he is not, then forgiveness is blameworthy. Allah the Exalted says, “Whoever pardons and sets the matter right, his reward is with Allah” (Shūrā 42:40).
Suppose someone assaults you, seizes your wealth, insults you, or the like—should you pardon him or not? The answer is nuanced: if the person is wicked and vicious, and your pardon would only embolden him to press on with his aggression against you or others, then do not forgive him. Take back your right with your own hand—unless you live under an Islamic authority, in which case the matter should be referred to those who wield legitimate power. Otherwise you may act yourself, provided that doing so does not cause a greater harm.
In summary, if the aggressor is evil and malicious, he is not fit for pardon; do not forgive him. It is better to claim your right, for Allah says, “Whoever pardons and sets things right…,” and in such a circumstance, pardon does not set things right.