Above all, such counsel will involve a careful examination of motivation and a re-examination of the trustworthiness and goodness of God who doesn’t call us to compromise in our devotion to him, but to trust him.
The Bible addresses the hardships that come with marrying a nonbeliever, so that's rather clear.
For what do righteousness and wickedness have in common? What harmony is there between Christ and Belial [Satan]?
What does a believer have in common with an unbeliever?
All of this is compounded when you and your spouse are living for different things.
To explore some of those things better, consider this article.