Few if any close relationships can exist when two people are not "yoked", that is suitable to be a team able to succeed.
2 Corinthians 6:14 (KJV) [SUP]14 [/SUP] Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
That instructs one Christian not to pair up in ministry with an unbeliever. Now go to 1 Cor 7, the whole chapter, for husband/wife wisdom.
That word "yoked" refers by analogy to a pair or larger team of oxen or mules/horses, etc used to pull a plow. They are harnessed together, oxen and mules big enough to be paired together using a large wooded beam to make a pair pace themselves perfectly together. One can't wander away to eat some grass while the other is pulling the plow. But when a farmer pairs a strong experienced ox with a weaker inexperienced ox, the strong one is weakened cue to litle help in pulling. The farmer driving the oxen has a terrible time plowing a straight furrow, the strong ox inevitably leading his side, but soon weakened from having to pull plow and the weaker teammate. if one of the animals stops and won't move, that of course prevents the willing animal from doing its job. If one becomes disabled from stepping in a hole, the other can't help the disabled mate, nor the farmer in plowing. If one is showing signs of frequent disabilities, the farmer ought not buy such an animal for that job. He should shop for one that matches up with those he already uses. If he pairs up weak oxen, the plowing might never be finished. It goes on and on.
God teaches we too ought to be matched, in friendships, dating, and especially when choosing a spouse. All the problems I listed above, but a few of all possible problems with mis-matching teammates, apply directly to our relationships. Choose wisely, Pray much over your choice. Let this be confirmed by counsel from Christian leaders. Some secular advisers will say you could change the man, and should give him room to improve. That philosophy has resulted in disasters for many marriages.