Today is 9/11, a day we can't forget. It's a tragic day that lead to more tragedies worldwide and still continuing to happen. All I can say is that peoples have not truly known God. I doubt that there were many atheists involved in carrying out the terrorist attacks and our counter strikes ~ both sides invoked God and saw the other side as the enemy or evil, but no one really knew the true God as revealed to us through Jesus Christ correctly. They either believed in God falsely or just followed their own will, overriding the Lord's. It's been like that throughout history. Jesus was right when he said that he had come for division (Luke 12). Just be sure that you have the humility and meekness to truly follow God's will.