1 Corinthians 7:12 (10–16) “But to the rest I say, not the Lord,”
I think we need to understand the uniqueness of the situation. Jews had been taught one way, one rule of order and now, as believers, they were placed in a different situation. So the question about how we live life now was important and especially in marriage.
Even though Paul is writing to the church at Corinth the majority of believers there were Jewish and divorce was only practiced by liberal Jews. But, Paul encourages us to keep in focus on who we now are (as believers) and what our purpose is.
That means that Paul is issuing a command for a situation not covered by any command Jesus made or endorsed. Jesus did endorse the Jewish Law (in it’s essence, Matthew 22:36–40), but it didn’t directly cover a decision to believe after a marriage had been consummated.
So when asking questions about marriage and divorce the Old Testament still has tremendous direction for the husband and wife. Yet, all of scripture warns us against divorce at all costs. Too many times we forget that God says, “the two shall become one flesh”, Genesis 2:24. One flesh doesn’t just mean have sex. It takes time and patience to become one with your mate, give it that time and effort.
Decisiveness involves learning how to make decisions based on an understanding of God’s ways and God’s will.