Paul teaches best practices to avoid sexual immorality in a variety of relationship situations.
From verse 1 it sound like Paul is addressing a very specific question.
God is to be honored in all things.
We are prone to treat gifts like gods. Some worship the gifts they have. Others worship the gifts they wish they had. Both are a poor substitute for Jesus.
Honor Jesus with the beautiful marriage he has gifted to us.
Be compassionate when dealing with people in all manner of relationship statuses. God specializes in redeeming and restoring.
Lord Jesus, help me honor you with my marriage.