So if sin and evil dont exist how do u rationalize the bombing?

You're so stupid that it's frustrating. You think the reason why people are able to make good or bad choices is because theres some red thing in a place called "Hell" and thats why we're able to make bad choices.

Sin and evil are concepts within your religion. They don't mean anything outside it.

As for the bombings, I consider them bad because I value life and don't want other humans come to harm.

Now as a reaction I'm mostly interested in why those bombings took place. What were the reasons and how can we prevent such things in the future. But judging from the average idiot in the USA, it will probably result in another retaliation just perpetuating a cycle of violence.

Sin and evil is your explanation. That doesn't make it the only one or the correct one.

Some people have no regard for human life. They are usually void of any emotion or care for others.

Random chance. Bombs go off across the world nearly every day

Those who did the bombings were merely ( As Richard Dawkins puts it ) " Dancing to their DNA "

Religious fundamentalism