The Church, which simply upholds the teachings of Christ, wants you to live a morally safe and happy life; to live freely without the potential for disaster.
Most certainly to help you avoid experiencing the pain of divorce yet again!
Hence, an unsaved spouse probably will, at least, severely hurt you spiritually, if not destroy your salvation.
I personally know people who have made this tragic mistake and have suffered incredibly in many ways, especially spiritually.
Divorced people get into dating with the best of intentions, but also with a serious handicap: You’re already used to giving yourself to your spouse and it is hard to tell your body that now things have to change.
Imagine an elementary school that has its playground along a busy city street.
Remember: The best thing you can ever do for your potential life's mate is to help him/her out spiritually.
Hence, your conduct and doctrine are both very important.
A theater stage is shrouded by a curtain until it’s show time… If you are divorced, you should be guarding your gift, the gift of yourself, with utmost care and protection until the appointed time arrives and you may reveal yourself again.
Safeguard the gift of your heart, mind, body and soul – the total donation of yourself in marriage – with the understanding of the sacredness and importance.