God created man male and female, after his own image, in knowledge, righteousness, and holiness, with dominion over the creatures.
Genesis 1:27 (NASB)
God created man in His own image, in the image of God He created him; male and female He created them.
The final supreme act of God, on the sixth day, was the creation of man. People today do not like to use the term man, because in their minds it means maleness, but God created man, male and female, in the image of God; therefore, all, male and female should be treated with the dignity afforded to the image of our creator.
Colossians 3:10 (NASB)
and have put on the new self who is being renewed to a true knowledge according to the image of the One who created him—
When we lie, we make God out to be a liar; when we steal, we make God out to be a thief; and when we are unfaithful, we make God out to be unfaithful.
Genesis 1:28 (NASB)
God blessed them; and God said to them, “Be fruitful and multiply, and fill the earth, and subdue it; and rule over the fish of the sea and over the birds of the sky and over every living thing that moves on the earth.”
Man is not to be abased and become like the creatures of the earth, but man is to rule over the fish, the birds, and every living thing the moves on the earth.
It is the command of God for man to be fruitful and multiply, to fill the earth and subdue it; therefore, the family is the basic structure of human society.
When Jesus was asked about sexuality, he went to the creative account; therefore, any sexual relationship that is not a marriage of one man and one woman is a deviation away from God’s plan.
 The Shorter Catechism, 10.