Magic is the divinity of man conquered by science in union with faith; the true Magi are Men-Gods, in virtue of their intimate union with the divine … - Eliphas Levi

"The sign of the Cross adopted by the Christians does not belong exclusively to them. It is kabalistic, and represents the oppositions and quaternary equilibrium of the elements. We see by the occult verse of the Pater, to which we have called attention in another work, that there were originally two ways of making it, or, at least, two very different formulas to express its meaning — one reserved for priests and initiates; the other given to neophytes and the profane. Thus, for example, the initiate, carrying his hand to his forehead, said: To thee; then he added, belong; and continued, while carrying his hand to the breast — the kingdom; then, to the left shoulder — justice; to the right shoulder — and mercy. Then he joined the two hands, adding: throughout the generating cycles: 'Tibi sunt Malchut, et Geburah et Chassed per AEonas' — a sign of the Cross, absolutely and magnificently kabalistic, which the profanations of Gnosticism made the militant and official Church completely lose.

In Black Magic, the Devil means the employment of the Grand Magical Agent for a wicked purpose by a perverted Will.

I will go further and affirm that magical circles and magnetic currents establish themselves, and have an influence, according to fatal laws, upon those on whom they can act. [...] The man who is eccentric in his genius is one who attempts to form a circle by combating the central attractive force of established chains and currents.