Does the Bible teach that we are to forgive under all circumstances? I answer categorically, vigorously, ardently, insistently that it DOES NOT!
The Living Word of God, Jesus Christ says,
“If thy brother trespass against thee, rebuke him; and if he repent, forgive him. And if he trespass against thee seven times a day, and seven times in a day turn again to thee saying, I repeat, thou shalt forgive him” (Luke 17:3-4 KJV).
What is being plainly taught here is that a condition must be met by the offender before we may pronounce forgiveness! The wrongdoer must first "repent," that is to say judge himself for his wrongful deed and then give substantiation of his sorrow over it.
Suppose that the offender does not repent? Then I am NOT to forgive him!
Repent RE'PENT, a. [L. repo, to creep.] Creeping; as a repent root.
REPENT', v.i. [L. re and paeniteo, from paena, pain. Gr. See Paint.]
To feel pain, sorrow or regret for something done or spoken; as, to repent that we have lost much time in idleness or sensual pleasure; to repent that we have injured or wounded the feelings of a friend. A person repents only of what he himself has done or said.
To express sorrow for something past. Enobarbus did before thy face repent.
To change the mind in consequence of the inconvenience or injury done by past conduct.
In theology, to sorrow or be pained for sin, as a violation of God's holy law, a dishonor to his character and government, and the foulest ingratitude to a Being of infinite benevolence.
To remember with sorrow; as, to repent rash words; to repent an injury done to a neighbor; to repent follies and vices.
However, let us not misunderstand the meaning of these thoughts. Even though the wrongdoer has not repented, I must not hold ill-feelings against him. I cannot hold hatred or malice in my heart. On the other hand though, I must not treat the offender as if he had done no wrong. That would be condoning the offense!
Does God ever forgive where there is no repentance? No! The Bible says:
“If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness” (1 John 1:9 KJV).
Lastly, if the wrongdoer has not repented, while I cannot forgive him and treat him as though he had not offended, I should pray for him. Here we see the value of Christ’s perfect example. If we cannot forgive, we can pray for God to forgive him. Arthur W. Pink, The Seven Saying of the Savior (Public Domain) (Paraphrase mine)