To the Christian Community: Why did God try to kill Moses?

Exodus 4:24-26 KJV

24And it came to pass by the way in the inn, that the LORD met him, and sought to kill him.

25Then Zipporah took a sharp stone, and cut off the foreskin of her son, and cast it at his feet, and said, Surely a bloody husband art thou to me.

26So he let him go: then she said, A bloody husband thou art, because of the circumcision.

Why didn't God tell Moses that he needed to be circumcised in a nicer way, or maybe just tell him about the covenant and tell him? Why did he have to go and try to kill him for something (especially since He doesn't tell Moses about the covenant with Abraham, or about circumcisions at all)?

Granted, he does state that Moses was an ancestor to Abraham in Exodus 3, but Moses was raised by The Pharaoh's daughter, so chances are he never learned of this whole "God" thing, especially since the Egyptians enslaved the Israelites and probably didn't share or pass on their beliefs. To add, they still didn't talk about the past covenants, but focus on the whole getting the Hebrews out of Egypt thing.

So why does God try to kill Moses for something they never talked about?

PS I'm an atheist.