The only people who should atone for the deaths of those people are the killers....and those who seek to emulate them, or cheer them on. A very small minority of Muslims worldwide.
Muslims, Christians and so on should not be expected to bear the responsibility for anyone's behaviour but their own. It's ignorant to blame all Muslims. They are no more to blame than a non-Muslim.
But we can blame Islam - the ideology that prompted these actions.
Buddhism, as an example, is fundamentally peaceful. Follow the teachings of the Buddha to the letter, and the very first rule to follow is "don't kill any living thing, for any reason".
That doesn't mean that other motivations & agendas can't creep in and motivate Buddhists to violent action. But fundamentally, Buddhism is peaceful.
The opposite is true of both Islam and Christianity. Follow the fundamentals of them to the letter, and death and destruction follows.
Of course, most Muslims do not follow the Koran to the letter - an acknowledgement that to do so would be horrific. That's why they don't - because they are decent people.