Atheists are, in fact, some of the most religious people.

First, they have a functioning God under whom they are subservient (normally it’s science or rationality, but mainly themselves), and that idea of God informs the way they live and interpret their lives. It informs their biases and determines their values, and governs any sense of morality or ethics they adhere too, or ignore.

Once that’s all settled all that’s left is the preaching.

And they preach all the time.