That verse fits in with the overall context - and the overall context teaches that the only way a Christian is free in a divorce is when the non-Christian leaves the marriage.

1 Corinthians 7:12-15 But to the rest speak I, not the Lord: If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away. And the woman which hath an husband that believeth not, and if he be pleased to dwell with her, let her not leave him. For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy. But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace.

There is a big difference between what it says above and what some others are teaching (that a Christian is not bound by ANY divorce).