The journey of heaven is journey where one has to cautiously by guided by God's will and God's word. One of the reasons why christains may not make heaven will the disobedience. When one disobey he/she devate from God's plan for his/her life.
When God calls a man either when he is in the mother's womb or when there is always a role his has to play. That role to obey to His will, you direction will be choosen by God, word of God become your daily meal which you take in the morning, at noon and at night.
Apostle Paul: in Galatians 1 vs 13-15 entails that he was called as a servant of God when he was in the mother's womb and as such his kept his body holy and under subsection to avoid sin as in the book of 1 Corinthians 9 vs 27.
John the Baptist: in Luke 1vs 15 john the baptist that baptised Jesus was called when he was in the mother's womb . The bible said it was his destiny to be great in the sight of men and God. He obeyed the will of God by avoiding wine or strong drink.
Jeremiah: in jeremiah 1 vs 5 entails that jeremiah was called to be a prophet in the mother's womb unto nations of the earth. The bible made us understand that his was ordained and sanctified by God.
Levi: in Hebrew 7 vs 9 , levi was called to be seevantof God when he was in the mother's womb, infact the bible said "levi the priest of Israeli ties that receives the tithes of Israel that he was destined in the loins of his father".
Thses men were called by God but they had a role to play which centers onnthe role of obedience and doing his will if they did not obey God and do his will they will cast away.
Thank you and God bless you as you read.