What if someone should say:  God has merely threatened sinners with eternal punishment to keep them from committing sins?


If He makes use of empty threats to keep us from injustice, then the promises He makes to lead us to justice are likewise worthless. But no one in his right mind would entertain such a thought. If God threatened us without ever intending to fulfil His threat, we should have to call Him deceitful instead of merciful. And that would be sacrilegious.

– St Gregory the Great, Dialogues, Book IV