On the surface, it might seem noble to forgive unconditionally. But unconditional forgiveness is usually motivated more by fear than by love. And because of this it's usually destructive. If a wife continues to forgive a habitually unfaithful and abusive husband unconditionally, her toleration of his behavior will probably result in even more abuse and disrespect. This kind of "unconditional" forgiveness expresses a determination to cling to the status quo. No matter how bad things are, this woman fears that things will probably get worse if she holds her husband accountable. Her passive acceptance of his behavior will probably encourage him to continue in his sin. Instead of her forgiveness being a helpful act of love, it is actually a violation of love that will hinder his growth toward Christ-likeness.
Jesus' specific teaching about forgiveness in Luke 17:3-4 makes it clear that forgiveness should follow repentance:
Take heed to yourselves. If your brother sins against you, rebuke him; and if he repents, forgive him. And if he sins against you seven times in a day, and seven times in a day returns to you, saying, "I repent," you shall forgive him.
Undeserved forgiveness and unconditional forgiveness are radically different. It takes courage and character to forgive those who repent and ask our forgiveness. If we forgive them, we expose ourselves to the risk of being hurt again. Their repentance doesn't earn our forgiveness in any way. They are still responsible for the harm they've done. But though their repentance doesn't make them deserving of our forgiveness, it makes them eligible. We can forgive them because of the example of forgiveness that God has given us in Christ (Matthew 18:21-35).
Unconditional forgiveness is an affront against justice and a denial of the significance of sin and its cruel effects. Undeserved forgiveness is an expression of divine love and the only basis of our hope for salvation.
In a flawed world, forgiveness shouldn't be given unconditionally. But we should always be willing to share the undeserved forgiveness we have received through Christ. We should be realistic in confronting our enemies, but we should also seek to love them and respond to them in a way that is ultimately in their best interest.