Does God predetermine everything?
ORIGEN: Pharaoh‘s heart was hardened in the following way: God did not want to punish him immediately and completely. Although Pharaoh‘s wickedness was enormous, God in his patience did not withdraw the possibility of conversion from him. Instead he struck him lightly at first and then gradually increased the blows. But although God acted with patience, Pharaoh was hardened by that very thing and became even more angry with God and contemptuous of him…. Therefore it is not that God hardens whom he wills, but rather that whoever is not softened by his patience is thereby automatically hardened.
God wills for all to be saved. Indeed, He fashioned man to live in loving unity with Him for eternity. Man’s predestination is this. However… Man is free to reject what he was destined for. This happened with Adam, and continues with us now.
Predestination does not mean predetermination. God does not say “this person will fail” and “this person will succeed” as though it were arbitrary. That would, in fact, mean that He is a terrible God who creates people for eternal misery. He knows what each person will choose in their own will (personal) and also wishes for the salvation of all (predestined from before creation for everyone), though this may be rejected by a person’s free will
+ “There is nothing that hinders us from finding faith. If we heartily desire it, faith at once becomes active. It is a gift of Our Master and a natural thing, even though it remains subject to our own freedom of choice.”. - St. Symeon the New Theologian
The Orthodox faith empathizes synergy and so though God desires all to be saved it depends on our response to this grace whether or not this comes to fruition.