>being good without a god
Atheism is the worst sin possible to commit in this life.
Sins like murder, torture, mutilation, rape, and genocide are sins against one's neighbour. God commanded us to love our neighbors. But that is only the second commandment.
The great and foremost commandment is to love God. Sins against God are worse than sins against one's neighbor. Impiety and in particular blasphemy is a sin against God, and atheism is the ultimate form of blasphemy (at least without certain knowledge of Christ, after which blasphemy becomes the one unforgivable sin).
Just by being atheists, atheists are committing the worst sin possible in the world, worse than any other sin that humans presently have access to.
No, atheists, you aren't good. Your sin, the sin of atheism, is worse than murder or child molestation. Atheists are about on par with or perhaps worse than theistic Satanists when it comes to being the most immoral people in the world. I say this as a former atheist.