I know that the Bible teaches both although it emphasises predestination over free will.
I have generally said that one must accept both by faith, ensure that they weight each with the same weighting they have in Scripture and accept that the two cannot be understood in relation to one another.
But I’m wondering if I am right on that last point. Perhaps I’m just being lazy. So below is a thought …
God uses natural wind currents and weather patterns to purposefully direct the winds to blow where he desires. It is not simply that God set up weather conditions at creation and now like a spinning top the winds blow accordingly on their own. Rather God has decreed where the winds blow but the means by which he accomplishes that is wind currents and weather patterns. The latter do not function independently – they function as God ordains. Nevertheless wind currents and weather patterns are real things.
Our very next breath occurs only by the decree of God. The means by which God causes this to happen is the functioning of our lungs. However our lungs do not act independently on their own – they function only by God’s enabling them to do so. Nevertheless lungs really work.
God foreordains all things that mankind will do – the means by which God achieves this is human free will. And yet even that means does not work itself out independently of God’s working. Nevertheless free will is genuine.
So predestination is the ends and free will is the means.
Ok only rough thoughts. I’m not sure if they help but seems like not bad observations.