The thing about death, is that when we die we are going to see God as He is. That is a huge event. Currently it would be impossible to see God as He is, because the created universe cannot contain Him, nor can our minds fathom Him. God is infinite and unchanging, and since physics teaches us that change (or causality) is the cause of time, in order to see God we need to step outside of time.
It follows, then, that we will also need to be unchangeable, otherwise we would still be within time and wouldn’t be able to see God as He truly is. Therefore God gives everyone the perfect chance to repent while still living, and everyone who is capable of being saved are therefore saved.