People act like God is not around primarily because it is very convenient for them to do so. If God is not around, people feel free to do whatever they want.
Students are at their most unruly when think they no teacher is present. Note that is not the presence of the teacher that keeps them subdued – it is whether they think there is a teacher present. If a teacher is present but disguised, the unruly students will not restrain themselves. Conversely, even if no teacher is actually present, the unruly students will restrain themselves if they (even erroneously) think a teacher is present.
It’s the same way with us and God. When we don’t think about His presence, we become unruly. To even think about His presence means we can’t keep indulging whatever thought or action we want.
Therefore, every atheist has a vested interest in his atheism. That is, for him to give it up would mean that he would have to stop living for himself and give an account to God. That’s why debates between unbelievers and believers are seldom cold and sterile affairs. The atheist has a very powerful inner motivation to not change positions: he does not want to have his life turned upside down. He knows that losing the debate would only be the beginning – and the smallest part – of what he does not want. (Agnostics face the same dilemma, but lack the boldness of an atheist to take a stand.)
Therefore, don’t think you can win over unbelievers with logic for there is something stronger than logic that is motivating them. It is their inner will to preserve life as they know it. This is foolishness, however, because no one can preserve life as he knows it. For this reason Jesus said that if we seek to keep our life, we’ll lose it; but if we lose our life for His sake, we will find it.
Give up wanting what you want and start wanting what He wants.
Act like Jesus Christ is around. Because He is.