Matthew 6:7-21; Must we forgive others?

The passage occurs in the narrative Lectionary, Year 1 (Most recently Feb 1, 2015). 

For my pound-it-out analysis of the Greek in Luke and Matthew's version of the Lord's Prayer, click here.

This week, I want to focus on the Bible verses 6:14-15:  (NRSV)
For if you forgive others their trespasses, your heavenly Father will also forgive you; but if you do not forgive others, neither will your Father forgive your trespasses.

It brings up the haunting question, must we forgive others to be forgiven?  Before we answer this theologically, let's dig into the grammar and words in the Greek (is there a linguistic way out of this theological conundrum!)

παραπτωμα (paraptoma, "trespasses"):  In Matthew's Gospel a couple of words are employed to talk about sin.  In the Lord's Prayer, the word is "οφειλημα" which means first and foremost, a debt.  There is also the most theologically loaded term of sin, a wrongdoing against God, αμαρτια, used when Jesus institutes the Holy Communion.  The word in this verse, παραπτωμα, means linguistically, "overstep."  (This is what "trespass" literally means.)
How does this offer us a possible out:  You could say that that this verse actually exonerates us from forgiving the sins of other people.  We cannot do this.  Only God can forgive sins.  Jesus' claim to divinity in Matthew (see chapter 9 and healing of the paralytic) rests on his ability to forgive sins.  But we can and must forgive missteps.

υμων (of yours):  The entire section is conjugated in terms of verbs and possessive adjectives in the plural form of you.  Another way to look at this passage then is that Jesus is speaking to the collective and not just individuals.
How does this offer us a possible out:  It doesn't.  In fact, it makes it a whole lot more complicated.

ουρανιος (houranios, ie, horizon", "heavens.")  If you notice, the first part of the passage speaks about the Father in heaven; the second half simply about your father.
How does this offer us a possible out:  Perhaps we are speaking about human judgements -- if we do not forgive others, our human piers will not forgive us.

αφητε (aphete, in various forms in this passage, "forgive")  This word provides two avenues for reflection.  First, it's meaning.  It can mean "permit" or "let go" in addition to "forgive."
How does this offer us a possible out:  If one reads this translating "permit" instead of "forgive" it has a slightly different meaning, one that is less about heaven and hell, but simply about how our attitude toward others becomes God's attitude toward us in life.  God becomes the universal tolerance karma instead of judge.
Lastly, this verb is in the aorist.  Aorist can be thought of as an inceptive aorist, meaning it points to the moment an action began.  So, "If you begin to forgive others their trespasses..."  Ultimately, this does not alter the meaning, it simply waters down the intensity.

To put it another way, the Greek in these passages does not intensify the English meaning.  If anything, they provide us with a more earthly than eternal framework for understanding its significance.  Regardless, our forgiveness before God and the forgiveness of others are bound together.  Jesus didn't wait until enough humans had forgiven each other to die on a cross!

I think I would want to thread a very precarious theological needle and offer this:  While on earth. the extent to which we experience God's forgiveness is intimately related to how much we extend forgiveness to others.  Forgiveness and the prayer life that accompanies this are a way of life for Christians.  That said, when it comes to heaven and our sins against God, this comes down to the cross, grace and faith.