The earliest manuscript of the Divine Principle was lost in North Korea during the Korean War. Upon arriving as a refugee in Pusan, Reverend Moon wrote and dictated a manuscript called Wolli Wonbon (Original Text of the Divine Principle). He then guided Hyo Won Eu, the first president of the Unification Church of Korea, to prepare more systematic presentations of his teaching with biblical, historical and scientific illustrations. Reverend Moon gave President Eu special instruction regarding the content of these texts and then checked them over meticulously. These efforts resulted in Wolli Hesul (Explanation of the Divine Principle) published in 1957 and Wolli Kangron (원리강론, 原理講論, Exposition of the Divine Principle) published in 1966. Since 1966, Wolli Kangron has been the text of Reverend Moon’s basic teaching.