 Following his release he led a life of travelling, speaking, teaching, and maintaining correspondence with communities of believers and individuals, expounding the principles of the Baháʼí Faith.There are over 27,000 extant documents by ʻAbdu'l-Bahá, mostly letters, of which only a fraction have been translated into English.Among the more well known are "The Secret of Divine Civilization", the "Tablet to Auguste-Henri Forel", and "Some Answered Questions".