1 Corinthians 7:16-17 New International Version
16 How do you know, wife, whether you will save your husband? Or, how do you know, husband, whether you will save your wife?
17 Nevertheless, each person should live as a believer in whatever situation the Lord has assigned to them, just as God has called them. This is the rule I lay down in all the churches.
(Now we can fuss over what does THIS mean ;^)
I love that scripture. To me it sounds like the context is new Christians making decisions about their previous life choices and circumstances that have present day consequences. Paul tells them to not make radical life changes - but to live your new redeemed, repentant “believer” life within those circumstances.
Now everything in their lives will be blessed by the reality of the new life in Christ.