He didn't create them God gave us free will to do what we please. He didn't just create us and say okay now worship me. He let us have the free will to choose our own path. He is all merciful. He just doesn't put people to hell just like that. We have the will to go about as we please. Its our life our choices. Not God's.
In all seriousness, it's best to avoid having to discuss questions like these. People tend to get into arguments and, during these arguments, they'll get emotional. Lots of anger and violence.
That's why I'm so cautious of questions like these, because it's an obvious trigger for a religious argument war to break loose.
I just wanted you, and everyone else, to understand this.
How do you know that atheists are going to hell?