Largely replying to questions put by Bediuzzaman's students, these Letters cover a wide range of subjects: they provide illuminating answers to many questions of belief and Islam; they contain brilliant and unique explanations of the truths of belief and mysteries of the Qur'an, which also illustrate the Qur'anic way of Knowledge of God opened up by the Risale-i Nur; they offer important guidance to contemporary Muslims concerning many questions ranging from nationalism to Ramadan;; in addition they include the celebrated Nineteenth Letter, which describes more than three hundred of the Miracles of Muhammad (SAW); the Twentieth Letter, which together with being an important lesson in "reading the Book of the Universe," provides extremely powerful proofs of Divine Unity; and the Twenty-Fourth Letter, which solves convincingly the mystery of the constant activity in the universe, and the change and renewal of beings.