In those days John the Baptist came, preaching in the wilderness of Judea 2 and saying, “Repent, for the kingdom of heaven has come near.”
-Matthew 3:1-2, NIV
Can someone be forgiven without repentance?
I do not think so.
If it was otherwise, why did John the Baptist need to preach a message of repentance to prepare the way for Jesus? Clearly, we need to repent to receive Jesus’ forgiveness and ministry. This is at the heart of salvation and our faith.
Sadly, though, Christian leaders often miss this in the context of marital infidelity situations.
They want forgiveness to happen, but they are not interested in calling the sinning Cheater to repentance so that they can actually be forgiven. Without repentance, a person cannot receive the gift of forgiveness as they fail to acknowledge the need for it by their unrepentant actions.
In some ways, we can forgive without our Cheater repenting. We can acknowledge their sin against us is secondary to their sins against God. Then we give our rightful claim to God for Him to handle. He can determine from their if they repent (and are forgiven) or do not (and are damned). It is no longer our job.
Even doing that, though, leaves forgiveness incomplete.
It only is complete when a sinner–i.e. Cheater–turns from their sins and thereby receives the gift of forgiveness. Baring such a turning–namely repentance–they remain unforgiven.