This is actually a pretty good video. The best part was at then end when the guy comes out of his house and says; "Did you guys hear what i just said. This is inappropriate! Take me off your list!" It also reminded me of some of the richard dawkins videos I have seen where he goes around preaching evolution to people.
John is not actually preaching Atheism if your reading it that way. If not...
He is driving home a point using satire and humor of which the tactics employed by some religions in way of proselytization suddenly becomes received in another light when the shoe is placed on the other foot.
Dawkins is adamant, but I'm not sure you could exactly call it preaching as most of his conferences are geared for audiences who are not theists (excluding debates of course) and he is not actually calling out for a reversal of religion to force it become an atheist society of which is why I don't view his conferences as preaching.
Some of his material obviously includes examples of evolution, but a large part of what he talks about involves the nuances of religions of which remains contrary and hostile towards already well established facts, its irrationality, and the effects that this has on society such as the debate involving schools etc. Stuff like that.