Unconditional Forgiveness?

Through the years I have heard preachers say that we should unconditionally forgive all who sin against us. I have seen some Christians practice this. For instance, a man kills and rapes your daughter, and you say to the man "I forgive you" even when the murderer has not shown any remorse for it nor asked for forgiveness. Well, brothers, the bible does not teach that. Notice these words of Christ:

"Take heed to yourselves: If thy brother trespass against thee, rebuke him; and if he repent, forgive him. And if he trespass against thee seven times in a day, and seven times in a day turn again to thee, saying, I repent; thou shalt forgive him." (Luke 17: 3-4 kjv)

Here forgiveness is conditional on the repentance of the trespasser. 

Some say that we should forgive those who trespass against us even if they don't repent. Yet, this is not even how sinners receive God's forgiveness. It is always followed by faith, repentance, and confession. Many scriptures teach this.

What think ye?