You ought to share the same faith in Jesus Christ and be able to pray and worship and commune together at the same altar. We need all the help we can get when it comes to marriage. These words of Jesus ought to make us very picky about the kind of persons we choose to marry. These words of Jesus should also make us think very hard before divorcing our spouses. God hates divorce.
Divorce is radical surgery with a blunt instrument.
It's never pretty, never clean. It always leaves open wounds and scars. Ignore those triumphal stories that divorced people tend to tell about how their lives were so much better after they got divorced. They're not telling you the whole story. Divorce is painful.