The Reformation Study Bible ESV study note on verse 15 states,
7:15 is not enslaved. Some interpret this statement to mean that if the unbelieving spouse deserts the marriage, the believing partner may remarry. The thrust of this passage, however, is simply that a Christian is not obligated to insist that the marriage remain intact. Such an insistence would prevent them from living in "peace".
To quote the verse, more foy my benefit as I type,
But if the unbelieving partner seperates, let it be so. In such cases the brother or sister is not enslaved. God has called you to peace.
As I read the verse, I tend to agree with Sproul's assertion as well as MacArthur's and the original posts thoughts. Especially in light of the verses before ad including 15:
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. If any woman has a husband who is an unbeliever, and he consents to live with her, she should not divorce him. For the unbelieving husband is made holy because of his wife, and the unbelieving wife is made holy because of her husband. Otherwise your children would be unclean, but as it is, they are holy. But if the unbelieving partner separates, let it be so. In such cases the brother or sister is not enslaved. God has called you to peace. (1 Corinthians 7:12-15 ESV)
