God created man in His own image, in the image of God He created him; male and female He create them. 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."…~ Genesis 1:27-28.
Jesus answered, "Have you not read that from the beginning the Creator 'made them male and female' ~ Matthew 19:4..., from the beginning of creation, 'God made them male and female" ~ Mark 10:6.
…‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh. So they are no longer two, but one flesh~ Mark 10:7-8.
For this reason a man shall leave his father and his mother, and be joined to his wife; and they shall become one flesh ~ Genesis 2:24. Therefore what God has joined together, let man not separate" ~ Mark 10:9.
Popular thinking is of the flesh and popular thinking never changes. What was popular before in terms of the flesh is still popular; especially sexual immorality. That is why the Bible gives us God's the above guidelines for a godly union.
There are other popular ideas out there. One is that Adam and Eve were just symbolic of many early men and women. Wrong! From one man God created mankind. There were no groups and or pockets of men and women all over the world. God started with only one man.
God who made the world and everything in it is the Lord of heaven and
earth and does not live in temples built by human hands. And
he is not served by human hands, as if he needed anything. Rather, he
himself gives everyone life and breath and everything else. From
one man he made all the nations, that they should inhabit the whole
earth; and he marked out their appointed times in history and the
boundaries of their lands. God did this so that they would seek him and perhaps reach out for him and find him, though he is not far from any one of us" ~ Acts 17:24-27.