When did the concept of family start?

Answer 1

When Adam and Eve began having children, the concept of family was started.

Genesis 4

1And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD.

2And she again bare his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground.

Actually the concept of family existed within the Godhead. The family is a representation of the Godhead. The Godhead unites in actions and collaboration to produce LOVE which is the existence of all things, visible and invisible. God's intention was for the invisible LOVE phenomenon to be paralleled into a physical world, but unfortunately conditional love born after the separation of man and God has pretty much done away with this parallel. Man, woman and God was to be united as a family to produce LOVE in a physical manifestation through children. How ironic is that some parents torture the product of God's LOVE and some even kill their children. It is why God never intended for selfish unities such as one night stands, homosexuality and other selfish perversions that are supposed to represent His LOVE and character but man has distorted into his own perverse and selfish imagination because he has freedom to do so! Hope this helps.