Jeremiah 1:5 Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations. Because God pre-knew Jeremiah and the choices Jeremiah would make before he was in the womb, God Predestined him to be conformed to being a prophet and for us we see: Romans 8: 29 For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. 30 Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified. Genesis 25 also shows us this, 23 And the Lord said unto her, Two nations are in thy womb, and two manner of people shall be separated from thy bowels; and the one people shall be stronger than the other people; and the elder shall serve the younger. 24 And when her days to be delivered were fulfilled, behold, there were twins in her womb. He knew them before they were born, and we see Romans 9: 10 And not only this; but when Rebecca also had conceived by one, even by our father Isaac; 11 (For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him that calleth: 12 It was said unto her, The elder shall serve the younger. 13 As it is written, Jacob have I loved, but Esau have I hated. God knows us before we are ever born and therefore we are called and predestinated before birth. God does this while giving us volition to make choices for Him or to reject Him, the thing is because of His omniscience He already knows the choices we will make.