When a man and a woman are united in marriage in the eyes of God, they are seen in God’s eyes as one, and inseparable. Paul describes this unity in his discussion of the hierarchy which God has established.
1 Corinthians 11:11,12 “Nevertheless neither is the man without the woman, neither the woman without the man, in the Lord. For as the woman is of the man, even so is the man also by the woman; but all things of God.
Paul mentions this in relation to the leadership roles which God has established. As described in verse 3: the man is the head of the woman; Christ is the head of the man; and God the Father is the head of Christ. But in verse 11, Paul points that although the man has the leadership role in the family, that the husband and wife are not separate from one another. The husband is not complete without the wife; the wife is not complete without the husband.
Remembering back to verse 3, Paul says that the husband is the head of the wife in the same way that God the Father is the Head of Christ. When you are married, the marriage is not without both the husband and wife. The trinity is not complete without Jesus Christ. The fact that the Father is the Head of Christ does not mean that Christ is below the Father, but that Christ followed the Will and Direction of the Father. Christ was guided by the Father even though both Christ and God the Father jointly form the Godhead, with the Holy Spirit.
Back to verses 11 and 12, Paul reminds us that although the man is the head of the woman, that does not imply that the woman is somehow beneath the man no more than Christ is beneath the Father. It also does not imply that the woman is powerless no more than it implies that Christ is powerless. There is a parallel between Christ and God the Father, and a husband and wife.