"Forgive us our sins, for we also forgive everyone who sins against us." Luke 11. 4
... but that's not how we say it in church! If you're Presbyterian you will ask forgiveness for debts because Presbyterians are concerned about money. (This bias is reflected in the Gaelic "fiachan" too.) By contrast, Episcopalians are mindful of their property so their request is forgiveness for trespasses - so the joke goes.
There is a serious dilemma at the root of the banter about how we say the Lord's Prayer. It arises from the fact that Jesus spoke Aramaic and would have used the word "khoba" which means both debts and trespasses. So which did he mean - and does it matter?
Well it matters because debts and trespasses refer to different sins: debts are unfulfilled obligations that we owe to others; trespasses are misdemeanours already committed. The Parable of the Unforgiving Servant (Matthew 18. 23-34) confirms that Jesus was concerned about the forgiveness of debts. And his prayer from the cross "Father forgive them for they do know not what they do" (Luke 23. 34) provides a similar affirmation for the forgiving of trespasses.
So we can be confident that Jesus has both interpretations in mind. The sting is in the tail of this fifth petition of the Lord's Prayer: "for we also forgive everyone who sins against us." It is not simply that Jesus expects us to be prepared to forgive those who are indebted to us and those who have trespassed against us... whenever they come seeking our forgiveness. He makes it a prerequisite of our right to seek forgiveness from God that we have already forgiven those against whom we have a grievance - even before they acknowledge their guilt and seek our forgiveness!
What gets me every time is not only that Jesus forgave his persecutors even while they tortured and murdered him. It is his patience and mercy towards me, even as I struggle with petty grievances, despite the mountain of guilt which he has already cancelled on my behalf.