1 Corinthians 7:36-39

However, if a man has decided to serve God as a single person, yet changes his mind and finds himself in love with a woman, although he never intended to marry, let him go ahead and marry her; it is not a sin to do so. On the other hand, if a man stands firm in his heart to remain single, and is under no compulsion to get married but has control over his passions and is determined to remain celibate, he has chosen well. So then, the one who marries his fiancée does well and the one who chooses not to marry her does better. A wife is bound by the marriage covenant as long as her husband is living. But if the husband dies, she is free to marry again as she desires—but, of course, he should be a believer in the Lord.