It's sometimes amazing to me how people can miss the obvious when it's staring them right in their face. In the Peanuts collection linked above, the first book contains an essay which frames Peanuts as an early shot fired by the "beat" movement and tries to link it to the political movements of the 60s even while admitting that Schulz was never political in his strips. But nowhere in the essay does it mention Christianity, which clearly had a tremendous influence on the strip, especially as it became more established and secure. Linus and Charlie Brown both frequently quoted the Bible in applying it to the situations they found themselves in.
The collections are great to read, but the essay is disappointing in trying to analyze the influences of, and on, Peanuts. It's especially disappointing since there were at least two books published in the Sixties discussing the Christian view of Peanuts, at least one of which was a best-seller, so the idea was already out there.
It's still the greatest strip of all-time, far outpacing Calvin and Hobbes and the Far Side in my opinion. The announcement that it would no longer be produced really depressed me and I really felt an emptiness. I'm glad they're rerunning the "Classic Peanuts" strips now. I don't know if I'm ready to face a comics page without Peanuts on it. I hope I'm never faced with that situation. Here's to another 50+ years of Peanuts reruns!