Tolstoy believed that the truth claims of different Christian sects were invalidated by virtue of the claims being mutually exclusive. Yet Tolstoy continued to regard religion as necessary (for life). It’s surprising that he does not take his analysis further to the scope of all religion. Different religions, not just different Christian sects, have mutually exclusive truth claims. Would that not, by Tolstoy’s own thinking, invalidate religion altogether?
It wasn’t made clear in the text (A Confession) how Tolstoy came to use such reasoning as it isn’t very effective when applied to other situations. Mutually exclusive models, theories, explanations, etc. are ever-present — the content and/or argument of each isn’t invalidated solely by its relationship to another. “Guilt by association” comes to mind.
Tolstoy later mentions that “true religion” has certain principles that are shared by all religions. However, how would he determine the truth of those against what he calls “false doctrine”? It seems that when Tolstoy searched for meaning in his life, he came to the “truth” of religion by its utility — it allowed him to continue living. However, such a method for determining truth is not effective. Suppose that, when told that praying to Chuck Norris increases life span, those who did so lived longer. Did they necessarily live longer because of the truth of the statement? No! Therefore utility does not necessitate truth.