The structure of the phrase "I felt relieved as I read it, vindicated, almost personally understood…" is not very clear to me.
It appears to explain why "I felt relieved", because I read it and almost understood it. The problem for me is the meaning of "vindicated" - "(I) vindicated"? It seems that before reading the book (The End of Faith), the author thought it was guilty to criticize religious moderates who respect other people's different faith; as the author went further in reading it, he understood the book's view and vindicated/proved the author of the book.
I am not sure I am on the right track.
What does "vindicated" mean here?
The End of Faith articulates the dangers and absurdities of organized religion so fiercely and so fearlessly that I felt relieved as I read it, vindicated, almost personally understood… Harris writes what a sizable number of us think, but few are willing to say in contemporary America… This is an important book, on a topic that, for all its inherent difficulty and divisiveness, should not be shielded from the crucible of human reason.
Source: The New York Times Book Review