2 Timothy 3:16
All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness.
1 Corinthians 7:6 (also 7:25)
I say this as a concession, not as a command.
1 Corinthians 7:12
To the rest I say this (I, not the Lord): If any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her.