God is the cause for predestination/election for heaven. God does not, however, predestine anyone to hell. Those that go to hell, do so on their own. The Church’s teaching on this is best understood by the following scripture:
Rom 6:23
For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
Rom 8:30 And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified. No one can be saved unless God initiates it. Romans 9 is a great chapter to see the plan of salvation.
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