As an atheist, one of the fundamental questions you get asked is, "Where do you get your morals without religion?" They may even go further and claim that you can't have morals without some diety telling you what and what not to do. They think that, because we don't believe in eternal punishment, there's nothing to keep us from acting badly. For some reason, it never occurs to the religious person that not wanting to hurt other people is reason enough to keep us from doing bad things.If what religious people think about atheists is true, and the only thing keeping your local churchgoer from raping and murdering the next person they see is fear of punishment by their God, that's not somebody I want to hang around with. Having morals without religion isn't hard. We all have a conscience, we all know deep down that hitting another person is wrong but that's just your empathy for a fellow human being talking, not an invisible man in the sky whispering creepily into your brain.
Religious groups like to pretend that their morals are absolute. There's right and wrong, white and black, and they are very clearly distinguished from each other. In the real world though, that's just not the case. There's plenty of gray space in there. Most Christian religions can't even agree between denominations on certain specifics. Is drinking alcohol a sin? Is homosexuality? Some think yes, others no. If people who all believe in the same God can't even agree on what is and isn't moral, how can they claim atheists have none at all? At least atheists don't pretend to have an absolute rulebook that lays all this out. There are disagreements among atheists, just as there are with the religious, about things like assisted suicide and the death penalty.Of course having a moral code or empathy for others doesn't mean people don't do bad things and we all know that bad people aren't just restricted to the non-religious. Plenty of immoral, sometimes downright evil deeds have been done by holy people. Some of them do it in the name of God or try to justify it as being a necessary evil to further the kingdom of God.
So why is it that religious people insist that morals come from God alone? Mostly, because it flies in the face of their scripture. If you don't need God to be a moral person, then their scripture is wrong about something and as soon as it's wrong about one thing, it could be wrong about everything. By being a moral person without God, you're removing one of the cornerstones of their religion and their faith gets shaky.
Good people, religious or not, have empathy for other people. That's all you need. No complicated rules or a list of commandments. While it comes from the Bible, even atheists agree that following The Golden Rule is a good way to live. But again, that's just empathy. You don't need an ancient book to tell you that. And you shouldn't have to live in fear of punishment in order to follow it.