Jeremy Smith, an always engaging and frequently provocative United Methodist blogger, argues in this post that Matthew 16:9 and 18:18 give the church the authority to determine what is sin and what is not.
Smith bases his argument on New Testament scholar Mark Alan Powell’s assessment of the rabbinical meaning of binding and loosing and what it means in Matthew 16:9.
I would argue that Matthew 18 is the more helpful verse for interpreting this question since it is placed in a fuller context than 16:9. Using the principle that the Bible can help us interpret the Bible, I read Matthew 18 as offering little support for the notion that the language of binding and loosing is a wide grant of authority over the very definition of sin.
Here’s what I wrote on Smith’s blog:
Interesting post, Jeremy. My take, FWIW, is that you are over-reading the matter when you suggest that this is a process for defining what sin is.
The context is the parable in Matthew 18:10-14 about seeking wandering sheep, which itself is a comment on those who cause someone else to stumble (vv. 6-9).
In Matthew 18:15-20, the fact of a sin is not under negotiation. If someone sins, go point it out (like the one trying to bring back the wandering sheep.) If a person does not listen, then a process of widening attempts to bring the person back to the fold ensues, but if they will not listen, at last they are to be cut loose. Verse 18 about binding and loosing, after all, comes right after verse 17 about treating the one who will not listen like an outsider. That sounds more like saying that who the church sends away, so will God.
I think it is significant in reading these verses that the next section of the chapter is about forgiveness. When one who has caused others to stumble or wandered away is brought back, forgiveness is the order of the day. To refuse to forgive one who will not have mercy on a wandering sheep brought back to the fold [is a serious offense to God].
To my reading, at least, that language about binding and loosing needs to be set in the overall context of the chapter before we can conclude exactly what is being bound and what is being loosed. I can’t see how chapter 18 can be read as saying “the church determines what sin is.” I don’t see where the text supports that conclusion.