In the section "what the thunder said" the crisis of faith is vividly displayed. One of the major reasons of crisis of faith in The Waste Land is spiritual aridity faced by the people of London due to the first world war. Not only this; the entire poem is scattered with the examples of crisis of faith. The denizens of wasteland have an indifferent attitude towards life and this arises in them as a result of crisis of faith.
Why not trying to find out what is really written about this topic - for example by consulting a bibliography or a bibliographic database like the MLA International Bibliography? There are hundreds of titles about Eliots "Waste Land", a few titles about faith in "The Waste Land". Maybe a close look into the "Cambridge Compagnon to T.S Eliot" will give substantial hints (Mcnelly Kearns, Cleo. "Religion, literature, and society in the work of T. S. Eliot." The Cambridge Companion to T. S. Eliot. Ed. A. David Moody. Cambridge University Press, 1994. )
It is also a good idea to browse through GoogleScholars results where you can also find some full texts (not only bibliographic data)