The third group of people consists of married couples of whom only one spouse has come to faith, the other spouse remaining an unbeliever. To this group, Jesus had given no direct instruction. Therefore, Paul gives these instructions himself (I, not the Lord
).
It is not that Paul’s own instructions carry less authority than those that come directly from Jesus. Paul writes as an apostle, an authorized ambassador of Christ. His instructions, too, come from the Spirit.
When it comes to a believer who is married to an unbeliever, the basic principle remains. The believer should not divorce. However, it may be that the unbeliever does not consent to live with him
(or her). Such a complicated situation requires special instructions from the apostle.
12 To the rest I say (I, not the Lord) that if any brother has a wife who is an unbeliever, and she consents to live with him, he should not divorce her.