The Sunday Lectures comprise more than 25% of all the lectures given by Peter Deunov. They are also considered his most significant oeuvre as they contain the key topics and subjects which would serve as a template for all future lecture series. The collection of lectures in this volume are organized chronologically and span the years 1919-1920, covering roughly one year. Almost every lecture begins with a verse from the New Testament, followed by a detailed analysis by Deunov, in which he examines the meaning of the verse. Deunov oftentimes explains the effect of Christ's words in scientific and mathematical terms, which he uses to answer the questions set forth by his listeners. On many occasions he receives peoples' questions as he's giving the lecture, a factor that contributes to the diverse nature of topics encountered throughout many lectures.

The course of these lectures is punctuated by two important events: The Paris Conference which officially put an end to the first World War, and the rise of Bolshevism in Russia. While the future of Bulgaria and all of Europe hung by the thread of these events, Peter Deunov insists that the real fate of mankind can only rest in the connection with the Divine. There is a profound Divine center within man, which anchors him to the eternal, and doesn't let him get rocked side to side from one popular uprising to another. This anchor is his safe haven, and whatever the individual does when in contact with this Divine origin will always remain true. The unity between man and the Divine is not conditioned by political episodes and the volatile nature of human opinion. It is rather and eternal oneness with the Divine principles that govern everything in existence.