The answer
In Christianity, marriage results in the couple becoming one in many aspects : physically, through the union of their bodies, spiritually, mentally, and psychologically. And it is this oneness which the Lord refers to.
H.G. Bishop Moussa
H.G. Bishop Moussa · Youth Concerns · 115
Faith Q&A › Youth Concerns › Relationships and Marriage
In the Bible, what is the meaning of the married couple being referred to as, “the two will become one” (Matt.19:5)?
H.G. Bishop Moussa, Bishop of Youth, Youth Concerns (Questions & Answers). Compiled by Lisa Agaybi. Coptic Orthodox Patriarchate, Bishopric of Youth Bookstore.