This is a very professional summation of the collected works of the Christian Mystic Dr. Stylianos Atteshlis aka Daskalos. And a very large collection of records it is.
Although this booklet is very complete in the concepts left by Daskalos, I feel it must be said that it is also like the Catechism material which religions hand out to children. Meaning, it lack the essences or, spirit "signature" ( borrowing a Boehme term here ). Therefore it is best to use the parallel publication "The Esoteric Practices" by the same publisher, as the handbook to apply this knowledge on ones own BE-ing-ness.
As always, the proof of any teaching is in the Living of it, not just the intellectual "Knowing" around it.