Supposing that my partner and I get born again after having four children in a cohabiting relationship. Should I leave my partner or does God consider me to be a married person who should stick it out as the mother of my children?
Since you have been living with your partner and have had children together, God would not want you to separate from your partner. God has defined marriage between a man and woman as a commitment. According to God, a couple is married when they make a commitment to one another,
Yet you say, ‘For what reason?’ Because the LORD has been a witness between you and the wife of your youth, against whom you have dealt treacherously, though she is your companion and your wife by covenant . . . (NASB) Malachi 2:14
Marriage is a covenant between a man and a woman. That is, when two people make a commitment to live together they are married. The Bible does not state that a formal ceremony such as a wedding is required. The question and answer titled, “Is it truly a marriage in the eyes of God if you are married by a Justice of the Peace?” The Bible does not state that a marriage certificate is required either. However, Malachi 2:14 does imply that the “covenant” was a formal commitment made in a formal setting such as a wedding ceremony. If you have never gone through a formal wedding ceremony, then we would encourage you and your spouse do so. It would be a blessing to you and to your children. It would be a positive testimony to your church.
God would not want you to leave your spouse or your children. God encourages us to remain together and separate only if an unbelieving partner wants us to leave. For more about unbelieving partners wanting a divorce, please read, “Biblical Divorce & Remarriage.”
Remain together and raise your children. You can show them the love of Jesus Christ by remaining together and showing them your love.
This I command you, that you love one another. (NASB) John 15:17
Reference Links:Is it truly a marriage in the eyes of God if you are married by a Justice of the Peace?
Biblical Divorce & Remarrriage