I had a cousin who pretty much hated God all his life but a few weeks before he died of stomach cancer, he repented and accepted Jesus Christ as his Lord and saviour. Before he passed, he said that he saw heaven and I’m pretty sure he probably went to heaven. He didn’t plan to have a death bed confession but it would appear he did have one. So, I thought perhaps deathbed confessions do work but now I don’t believe we should take it for granted. Please watch:
Why believe this person? He was a Christian, suffered a heart attack and was going to hell:
God is not mocked:
Galatians 6:7 King James Version (KJV)
7 Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap.