From the introduction:
"This is the great Grimoire, containing the rarest secrets in the world. The great laws of magic. Here you shall find secrets chants for the Holy Spirits of the Darkness. The throne of the Apostles shall be assumed by the one who has been entrusted with the key to the Kingdom of Heaven, in the words of the Lord Jesus Christ to Saint Peter: 'I shall entrust thee with the key to the Kingdom of Heaven', and he alone shall have the power to command the Lord of Darkness and his servants. And they shall be his servants also and shall bring him honor and glory and worship. Again in accordance with the Lord Jesus Christ's words, 'Thou shalt serve only one God'. By the power of the key to the Church, thou shalt become the ruler of Hell."
~Preface of the Bible Black