How is God the author of marriage?

First,“God created mankind in his image;in the image of God he created the mmale and female He created them”(Gen. 1:27). Since man and woman are created in the image of God, who is Love, man and woman carry an innate calling to love. Marriage responds to a fundamental desire and need to give and receive love.Second, as male and female, God created man and woman with a physical complementarity that is uniquely able to collaborate in His work of creation. The very nature of man and woman is prepared for the possibility of marriage and the welcoming of new life. Third, Holy Scripture affirms that it is good for a man and woman to belong to one another and form a bond of communion: “It is not good for the man to be alone”(Gen. 2:18) ….”That is why a man leaves his father and mother and clings to his wife, and the two of them become one body(Gen. 2:24). In the New Testament, Jesus invokes God’s original plan for mankind as an unbreakable union of two lives by recalling the plan of the Creator in the beginning: “So they are no longer two, but one flesh”(Mt. 19:6). In the divine plan, marriage is the exclusive, indissoluble communion of life and love entered by one man and one woman. Between two baptized Christians, this covenant is a sacrament.