I saw a post somewhere of a man bewailing his losses and downfall since he got married to his wife due to some powers using her to pull him down. Someone may be a born again christian, but you don't know what spiritual forces are fighting against him or her, (which will also fight you when you enter the family) or the family background where the person is coming from. People have gotten into problems they never imagined they would find themselves, some didn't even live to tell their story just because they never bothered to ask God about the person they want to marry, or were blinded by love, or maybe they rejected the choice God made for them. That's why we dont need to marry because someone is beautiful, handsome, rich or because we are in love. Marriage is way deeper than physical qualities, possessions or feelings. Seek the face of God, let Him guide you as you make your choice of who to marry. He can never mislead you. Even if the person has a bad background or has a problem spiritually and you get a 'go ahead' from God after praying, then you have done your part, God will handle whatever comes your way there.