We can be certain that Mohammad Atta was sincere in hids beliefs.
We can be certain that the god he sincerely believed in and gwave his life for is unlike the God I worship in nearly every respect.
A few weeks ago on the protest line I had a young man scream in my face that he hates me, and when I told him i'd pray for him he said something quite blasphemous about any God that would have me. I did pray for him, right there and several times since. I cannot conceive of a God who would view as equal the prayer of Atta for success in killing the infidel and my prayer for a man who hates me, just because we are both sincere in our prayer.