For if you forgive others when they sin against you, your heavenly Father will also forgive you. But if you do not forgive others their sins, your Father will not forgive your sins. -Matthew 6:14-15
Here is how I understand these words of Jesus in light of, what I believe to be, the "unconditional forgiveness" pictured throughout the scriptures.
I referred to, but didn't mention, Matthew 18 in yesterday's post, where Jesus gives instructions to his followers on how to deal with a "brother who sins against you". He essentially teaches that if someone has wronged you, then you should go to them and seek reconciliation. Jesus seems to put the burden of forgiveness and reconciliation on the one who has been offended,and not the other way around.
I have written before about how I think Matthew 18 teaches an endless pursuit of reconciliation, rather than the commonly misinterpreted three step excommunication process.
I have also written about how I see repentance as a response to forgiveness, rather than a condition for obtaining forgiveness. I think this is best seen in the parable of the prodigal son.
So when Jesus says that our forgiveness from God is dependent on whether or not we forgive others, I think there is more than meets the eye and I see this statement as more hyperbolic than literal. Jesus is essentially relating the way we forgive others to our forgiveness from the Father, or at least our understanding of the Father's Forgiveness.
The way we understand God's forgiveness will affect how we Forgive others. If we can not trust that God has forgiven us, if we can't accept that, then how are we going to extend forgiveness to anyone else. But when we come to accept and understand that God has indeed forgiven us, and We choose to live by faith in that forgiveness, it is then that We will find ourselves more willing to extend forgiveness to others.