In the book Genesis we find the genealogy of the first man and who he fathered until God changed the landscape of mankind. Adam (the first man) fathered many children, but Adam is widely known for fathering Cain and Abel. Now after Cain killed his brother, Adam Father one more by the name of Seth through him all the world is physically connected back to Adam.
Though Cain and Seth would go on to father children of their own, the world in itself became a vial place unstable and unfit for mankind to continue. God told a man named Noah to build an Ark and through Noah’s obedience, God saved Noah and his family from the complete destruction of the earth in which God drowned every living creature on the earth except for the chosen people and animals that were instructed to survive the flood with Noah and his family in the Ark.
Noah had three sons: Shem, Ham, and Japheth all of whom where chosen by God to repopulate the earth, and through these son’s of Noah they each began producing generations of people to repopulate the earth. One of the son’s of Noah named Shem would be the chosen son that through his lineage would be God’s chosen to become the father of nations.
After eight generations of sons and their sons, Shem’s seventh-generation grandson Terah produced a male child named Abram. It was God’s intent to call Abram to be the father of many nations through which God Himself would establish His Kingdom on earth through a child that would be born through the bloodline of Abram.
God has done this so that you could have a chance to be one family under God both in the physical and the spiritual. No matter your belief, God used Abram later to become Abraham so that all men on the earth could trace their lineage back to their earthly father which would give access to their heavenly Father.
Once you know it can never be taken from you.