"So there may be some who lean toward believing in a pre-destined life with God through Christ, but have not yet yielded themselves to Christ fully...."
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.
Does not "Before I formed thee in the belly I knew thee" means that God, before you were born, knew you would accept or reject His gift of salvation???....Did He not make that determination based on His knowledge of you????
It would seem to me, that the Prophet Jeremiah is being spoken to specifically by God about his calling to be a prophet to the nations. And Jeremiah was making inquiry as to understand why God separated him for this purpose.
This did not mean that God did not give Jeremiah free-will to accept or reject God's desire for him to be a prophet. But Jeremiah did accept this gift from God.
God's knowledge of us does not predestine our free-wills. God offers Himself to all, through His Son, Jesus Christ.
Now is the acceptable time of God's favor of salvation.(2 Cor 6:2)