Bertrand Russell is considered one of the foremost intellectuals of the early 20th century. He spawned a whole generation of apologists to defend the faith against his arguments. To be fair, though, Russell is as much an ideological atheist as a practical one (and it should be noted that his profession of outright atheism is significant), but at least in the title essay, he focuses largely upon organized religion as opposed to faith itself. In a practical context, Russell is an antitheist, that is, he sees religion as something that is 1) based upon fear of damnation and 2) inherently harmful to society. He builds upon valid points: historically, religion (or the abuse of religion) has proved an incredibly destructive force. All the traditional examples suffice: the Crusades, the Inquisition, Islamic terrorism (obviously, Russell didn’t use this one, but modern readers understand), &c. It would be logically fallacious to abstract The Church into a unified villain, but Russell’s speech avoids that pitfall by failing to broach that subject. That sort of abstraction, even when logically distinct, is still the subject of furious debate to this day.
Russell focuses especially upon sex, and the drive that pushes humans to do an incredible number of very wonderful and very stupid things. He also notes areas where the traditional church teaches about sex appear to conflict with what seems “natural.”
To be entirely honest, this collection of essays began a slow decline after the first (title) section. Largely, it’s reiteration of already-broached points. I found it difficult, by the end, to stay interested. One could probably read the first essay and then simply pick & choose from the rest without diminishing his/her understanding of the book.
To someone who already subscribes to Russell’s ideas, it will be nothing new or revelatory: Why I Am Not a Christian is a general, if potent, explication of agnostic-atheist metaphysics and antitheist moralism.