A wise man once described predestination like a door inscribed “Come All!”.
Once you entered in you’d find the sign: “Welcome Chosen Ones!”.
I asked this same question as I was struggling with Christianity and God.
The answer for me, came in looking at another of those common Biblical critiques... creationism.
In reading scripture (not to put down Theologians, Philosophers, etc, but if I’m looking for the things of God, I will first of all see what God has to say for himself. Afterwards, I enjoy comparing my thoughts to those of notables throughout history), the crux of the issue was time.
Is God bound by time, or is time merely one of His creations, and He is in essence ‘outside’ of time?
Please look through scripture yourself to consider this idea.
The answer that came to me, was that God is clearly outside time. He not only sees the present and the past, but also knows the future, because He ‘sees’ it. Prophesy, predestination, etc are all offshoots of this.
God prophesies because He knows what WILL happen.
God KNOWS what our choices will be, because he has seen them.
We have been given ‘Free Will’ to choose whether to follow God or not, yet we are also ‘Predestined’ because God knows the choices we will make. Not because He forced us to do them, but before we were born, He knows our future.
Our destinies are known to Him before we were born, and He knows the choices we will make using our Free Will.
What if PREdestination(knowing the end of a journey) meant that "He (Christ) came to SAVE(destination-heaven) His people(God gave Him before the foundation of the world) from their sins(the fallen state of man)? and His people, while here on earth, have the free-will(their choice) to choose whether or not to serve(keep his commandments) Him.
Once you entered in you’d find the sign: “Welcome Chosen Ones!”.
I love that one!