What is the context of the "unequally yoked" passage? 2 Corinthians 6:14 is the well known "unequally yoked" passage. While the common interpretation is that it is about marriage, the heading translators added in NIV is "Warning against Idolatry", and there was nothing about marriage.


Was it ever discussed what sort of event or situation that Corinthian church was in that inspired Paul to write such a passage?
What other interpretations exist of the "unequally yoked" passage that Bible scholars have proposed?
How did the idea that this verse refers to marriage come from, given that marriage was not mentioned in 2 Corinthians chapter 5, 6 or 7?
Paul is teaching about all close relationships between believers and non-believers, and while this could include marriage, it would also apply to other areas of life, for example a business partnership. The context of the passage (verses 15 to the end of the chapter) talk about how the beliefs of the unbeliever could lead the believer astray, and while I can see how the passage could be headed as a warning against idolatry, since the passage in question seems to be more than that I don't think the heading is the best possible choice. Both the RSV and NRSV group verse 7:1 with 6:14-18 in one section, which adds the verse


  Since we have these promises, beloved, let us cleanse ourselves from every defilement of body and of spirit, making holiness perfect in the fear of God. [NRSV]


and the NRSV uses for the heading of the passage "The Temple of the Living God." [The RSV--or at least my copies of it--does not add section headings.