Perhaps the part of this passage that we should pay the most attention to is, "Now for the matters you wrote about." Obviously, there is some struggle in the Corinthian church about what to do with marriage in this new Kingdom of Jesus, and Paul answers their questions. It's really unfortunate that we only have one side of this conversation, but the apostle keeps his focus on the love that Jesus gave us to share, living out in the Spirit, even in relationships.