Humans are humans. Humans the world over do the same things, regardless of culture, technology or security. They fight, they succumb to greed, they kill, they hurt each other. This is true in the most advanced and the most stagnant societies.
The removal of religion isn't going to stop these things from happening, especially when the whole point of most every major and minor world religion is peace, love, etc. Humans take these religions whose spokespersons (Buddha, Mohammad, Jesus, etc) advocate loving thy fellow man and turn them into tools for violence and hatred, the exact opposite of what they're intended for. Remove religion and people will take Winnie the Pooh and use him in the same way. Why? Because they're human, and they're looking for reasons to act on the human impulses they already have.
You're saying that if we remove hammers from the world then people will no longer pound nails. I'm saying in lieu of hammers we'll use the flat sides of wrenches. Regardless, those nails will still get pounded.