Well my opinion is not Calvinism and is not Armiaism. I really don't the answers to some key concepts that I feel are still a mystery. I know we have free-will to do evil, just as Adam & Eve chose not to follow God's command in Eden. But I also know that their are verses in the Bible that do have to be explained that seem to indicate that we are drawn to God, ie "You will not come to me, unless the Father draws you". God knew us before we were created. Now exactly what that means, I'm not sure. It could be because He is Omnipresent and not held to time as we are on earth that the past, present and future are not deliniated and separate to Him. Which would at a high level mean that even though we live our lives in the present for us, that could not be the present for God. The past, present and future could all be at the same time, so then He would have known us before we were born, those of us who have a relationship with God through prayer and faith. I do not take a hard line either way. There are verses that support free-will, even Lucifer had free will in order to rebel and since he took 1/3 of the angels with him, that means the angels had free will also and that 2/3 chose to stay with God.
So somehow God knows us before we live our lives, yet He knows what will happen in our lives and what happens to the earth and how everything goes down and Revelation has been written about the future that hasn't happened yet. God also knew in the Old Testament what exactly would happen to Christ. It is written I believe in Isaaih 53 . So obviously God knows it and I don't say that I totally understand but I think it is the element of time.
The word 'predestined' is used several times and I'm not sure if we have the word right as it has been translated from Greek or what that would mean except that God is out of the realm of time. But that cannot be proven to me nor not proven. It is an I'm not sure. I think the word predestined could mean before time in our understanding came. Yet we live within time. Somewhat confusing still to me but I don't know how big of a deal it is how we have come to Christ, but the fact that we have and we will spend eternity with Him.