Actually, it depends on different life events. Some people for example never had the opportunity to have a spiritual education. For them, it is hard to say that they know God or understand a religion. Of course, knowing God has nothing to do with religion. I agree with that. But religious education is very important. Most atheist just like religious education. Actually, they just do not know about spiritual life. They think they are cool by saying they believe in nothing. It is strange. How can you be alive and say you believe in nothing? You may not believe in man-made religions. Ok! But in God? please be reasonable.