Again I say to you that if two of you agree on earth concerning anything that they ask, it will be done for them by My Father in heaven. So when a person has sex with another person, that is only physical, not a spiritual link, it becomes a soul-tie. Not a spirit-tie. If a person or couple come to Christ and are renewed in their spirits, then God can join their spirits together as one before Him. After a couple becomes one spirit, and one flesh, they spend the rest of their married life working to become one soul.
Marriage is a uniting of two spirit beings.
That is why a marriage ought to be between two people who are born again. In this sense, their marriage takes on a whole new dimension and significance. I hope that will answer your question, please get back to me with any questions.