Need parental advice

Ok so the other night I was reading the bible with my 4 year old. We were reading about Adam and Eve and came across the part where God says "if you eat of the tree you will surely die". So like a typical 4 year old, he started asking a lot of questions and I tried to explain to him how death entered the world through Adam and eve's sin. Then I found out tonight that now he's telling people " if your bad, God will kill you".
Oops, that wasn't the way I wanted to get the message across. And now I have a few people in the family pretty upset with me. So the advice I want: how do I fix this? And how do I teach him these things in a way I can sugarcoat them yet at the same time not lie.

Ya, he's asking me the questions about death. That tells me he's old enough to start talking about it, since he's asking me the questions. It's just hard to sugarcoat it without lieing. I don't want him growing up thinking if your good you go to heaven. I want him to understand we go to heaven because of Jesus, not because we're good because that's heretical. Obviously I'm not gonna get into the topic of hell anytime soon though. But I want him to understand this in a way a 4 year old can grasp it yet not scare the pajibas out of him.

Thanks everyone.