The free will argument demonstrates that christians don't understand free will.

[Chad32]

I'd be careful of saying you need to earn your way into heaven, as some christians are very against that. Jesus does say faith without works won't cut it, but there's also a verse saying good works are like filthy rags to god. Faith is more important than works, which is why I worry that people like Hitler are actually in heaven. I would think that good works would trump anything else, but it's harder to get people to convert if you tell them that being a good person gets you into heaven more than anything else. It also devalues Jesus' death.

I've heard older translations say that Ra hardened his heart, but since they didn't want to say definitively that other gods really exist, it was changed to Yahweh doing it. That's the best explanation I've heard, though not in sunday school class.