Kuzari

Sources explaining Kuzari Principle and the rational basis for faith in G-d:

1. Gutnick Rambam, chapter 1. I think this is a superb book, by far not only as the Rebbe’s commentary on the 8th and 9th Principles of Rambam, but mainly as the exposition of how Chassidus Chabad views nigleh: its origins (spiritual and physical), its process, its evolution, etc. Another three chapters from the book: “Co-Existence of Contradictory Truths in Judaism”.

Interesting quote pertaining to the current events:

On the night of the Fifteenth of Nissan (Pesach) it is a mitzvah to recount the story of the Exodus from Egypt in response to a question from one’s son: “When your son will ask you... ‘What is this?’ you should say to him, ‘With a mighty hand G–d took us out of Egypt’ (Shemos 15:14)”. But even after the son’s question is fully answered on the first night of Pesach, he nevertheless is required to ask it again on the second night! So we see that questions and initial presumptions are as much a part of the Torah as the answers themselves, such that they must be repeatedly studied and emphasized.

2. Having said that, I think the first chapter of the above book is not the best source on Kuzari in existence. To date, I believe the clearest explanation of Kuzari Principle and rational basis for belief in G-d is one by Rabbi Dovid Gottlieb in Chapter 6 of his book (I would also read chapters 2 and 3 for general discussion of how one should approach the reasons to be religious).

(I am well aware there are many books explaining the book of Kuzari in detail. First, I am only referring here to online sources. Second, I am talking about specific explanation of Kuzari Principle and clear elucidation of its logic and application.)