en. 2: 24, Matt. 19: 5 and Eph. 5: 31 - "For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh."
The Concept of Becoming One is an intriguing one, there are so many interpretation of what Becoming ONE looks like, at a Q/A time recently, I was asked what becoming one looked like sexually with the person quoting 1 Corinth. 7: 2-5 (obviously for personal gain and out of context).
In my opinion, the Concept of Becoming One must be viewed and interpreted from the Concept of our existence. We are spirit, soul (mind, will and emotion) and body - so we must learn what it means to Become One - in spirit, in our soul (mind, will and emotion) and in our flesh.
As explained by the Bible, it is almost impossible to Become One, without both persons accepting Jesus Christ as Savior and Lord, we cannot Become One with someone who have another worldview or who's view of Christ and His kingdom is different from ours, this is why "being unequally yoked" is a BIG DEAL, or else Becoming One, is extremely difficult.
In spirit: we Become one in spirit - when both husband and wife, have both individually made Jesus the Christ as Savior and Lord, this act when truly done, brings the Holy Spirit (God's Spirit) to abide in us, helping us to Obey God's written Truth and guide us into all Truth.
When this is done, then both individual have the same SPIRIT, and when yielded to Him, are both set on the same path of Faithfulness and Obedience.
In soul: our soul includes our mind, will and emotion. Human soul is very fluid because it is influenced by lots of of attributes such as nature and nurture, it changes quickly with circumstances - particularly hormonal flow, so becoming one could be a challenge initially for a new couple, but could be achieved eventually.
Human mind however is a different ball game. When we become born-again, we are told (and helped by the Holy Spirit) to die to self and be led by God's Spirit exclusively, such acts according to apostle Paul, lead to Transformation (having the Mind of Christ) by the renewing of our mind with God's WORD.
As surrendered believers or transformed humans, it now becomes easier to surrender our will to God's perfect will - see Rom. 7: 15 and Luke 42: 22.
In flesh (body): there is something about sex that transcends just the physical act, in-fact the Bible calls it a mystery. We know from psychology that having sex with someone brings intimacy that is emotional, some would even argue spiritual. Hence, the Bible clearly spelt out that sex is "strictly" for within marriage, it is a sin outside of the marriage bound of a man and a woman.
It becomes easy to Be ONE in all three nature of our being - when we believe and accept Christ as Savior and Lord, and His Spirit is leading and directing us. Becoming One in spirit, in our soul and physically is easier and achievable albeit slowly and consistently.
William Femi Awodele is the Executive Director of Christian Couples Fellowship International, Inc. and a Vice-Chair of Embrace the Heartland in Prayer (http://www.prayheartland.com)