This book consists of fifteen letters by Shaikh 'Abd al-Qadir al-Jilani. Articulated in a sublime mystical language, the letters describe spiritual experiences that are attained through striving against one's base desires and committed devotion to Allah. They are written in a peculiar style whereby each sentence or group of sentences is followed by a related Qur'anic text, which is often a part of a verse. The text is effectively a Sufi experiential interpretation of the quoted Qur'anic verses. This peculiar style of the systematic pairing of mystical words of the Shaikh with a Qur'anic verse has produced an immensely beautiful text with a highly poetic tone. This translation of the book is based on three manuscripts. The first is in King Saud University in Saudi Arabia, the second is in the Bodleian Library at Oxford University, UK, and the third is kept in the Special Collections Library at Michigan University, USA. These memorable writings of a great master include: • Fifteen letters by Shaikh 'Abd al-Qadir al-Jilani • A mystical interpretation of Qur'anic verses • Beautifully articulated experiential spiritual advice