Paul says that such a marriage is still honoured by God. So long as you and your unbelieving husband/wife can live together in peace, you are to remain with them and by your good behaviour, you may win their respect which might, by God's grace, lead to the conversion of that person.
1 Corinthians 7:12-16 If any brother has a wife who does not believe, and she is willing to live with him, let him not divorce her. And a woman who has a husband who does not believe, if he is willing to live with her, let her not divorce him. For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband; otherwise your children would be unclean, but now they are holy. But if the unbeliever departs, let him depart; a brother or a sister is not under bondage in such cases. But God has called us to peace. For how do you know, O wife, whether you will save your husband? Or how do you know, O husband, whether you will save your wife?
I hope you have found this helpful.