Jakob Böhme – The Threefold Life of Man, 1620.

“The Human Spirit in its Threefold Form has all the Three Principles in it, viz. the Kingdom of God, the Kingdom of Hell, and the Kingdom of this World; and it speaks forth from itself, from the source, and form, of every being, whether it be Heavenly, Earthly, or Hellish, as it has been spoken forth by the Spirit of
 God from Eternity, in the Invisible Substance of the Eternal Nature, as a figure or Spirit of the Word of God; and was without Substance, till the Alpha and Omega, and in the Alpha and Omega, in the beginning and end: so also the Spirit of man speaks it forth in Beginning and End without Substance, for the
Substance was once created in the Creature. Thus you see how we stand in a Threefold Life: the Soul stands upon the Abyss, between two Principles, and is tied to them both; and the body merely in the Spirit of this world; and therefore that seeks only after eating and drinking, power and honour, for it belongs to the Earth, and cares little for the poor Soul which comes out of the Eternity, and belongs to the Eternity. 

God says: “I am Alpha and Omega, the Beginning and the End.” This word makes a Beginning, and God in the Number Three is the Beginning, and it also makes an End, and that is the Eternity, and also God: For before the time of this world there was nothing but God, from Eternity; and after this world, there will be nothing but God, in Eternity: but the cause why we comprehend not this, is because there is no Comprehensibility in God. For where there is a Comprehensibility (as there is in the Trinity) there is Beginning and End. And therefore we are shut up in Darkness, that we might labour and manifest God; just as concerning the seven forms of Nature, what an Eternal labour there
is therein, so that one form generates another, till they are all brought to
Light, and so the Eternal is Manifest in a Threefold Form, which otherwise
would not be known.”