The Bible last I checked
granted I have not memorized every verse so if you have a verse that corrects my thinking let me know!
The point is we have free will and we need to make sure we reach out to make heaven crowded. God is the beginning and the end and has our plan already in place... like he knew before we were born we would be chatting now!
We need to do be His servant and we might be in His plan to reach out the one who has been chosen.
Ephesians 1:4-5
Even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will,
Romans 8:29
For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers.
1 Timothy 4:1
Now the Spirit expressly says that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons,
Romans 8:13 New International Version (NIV)
13 For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live.
John 6:44
No one can come to me unless the Father who sent me draws him. And I will raise him up on the last day.
God has predestined us, God has drawn us but that doesn't mean we cant fall away through continuing in sin (acts of the flesh) and through turning to another gospel.