I say that it is OK. It does not matter whether a spouse belongs to a non-Christian faith, or is a Christian of a different denomination where their a differences in worship and practice [Catholic to a Baptist for example], the apostle Paul had this to say:
The Apostle Paul said this:
..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:... (1Corinthians 7:12-14 KJV).
Sometimes, contrary to what a couple expect, differences in religion may be insurmountable and the couple decide to divorce. But there may come a time when one spouse will embrace his/her partner's beliefs, so divorce should really be a last resort.