From: _Magick Without Tears_ by Aleister Crowley

[Crowley on Syncretic Religion, and Names of Gods]

   3. Now then to your old Pons Asinorum about the names of the Gods!  Stand in the corner for half an hour with your face to the wall!  Stay in after school and write Malka be-Tharshishim v-Ruachoth b-Schebralim 999 times!
   My dear, dear, dear sister, a name is a formula of power.  How can you talk of "anachronism" when the Being is eternal?  For the type of energy is eternal.
   Every name is a number: and "Every number is infinite; there is no difference." (AL I, 4).  But one Name, or system of Names, may be more convenient either (a) to you personally or (b) to the work you are at.  E.g. I have very little sympathy with Jewish Theology or ritual; but the Qabalah is so handy and congenial that I use it more than almost any --- or all the others together --- for daily use and work.  The Egyptian Theogony is the noblest, the most truly magical, the most bound to me (or rather I to it) by some inmost instinct, and by the memory of my incarnation as Ankh-f-n-Khonsu, that I use it (with its Graeco-Phoenician child) for all work of supreme import.  Why stamp my vitals, madam!  The Abramelin Operation itself turned into this form before I could so much as set to work on it!  like the Duchess' baby (excuse this enthusiasm; but you have aroused the British Lion-Serpent.)
   Note, please, that the equivalents given in 777 are not always exact. Tahuti is not quite Thoth, still less Hermes; Mercury is a very much more comprehensive idea, but not nearly so exalted: Hanuman hardly at all.  Nor is Tetragrammaton IAO, though even etymology asserts the identity.
   In these matters you must be catholic, eclectic, even syncretic.  And you must consider the nature of your work.  If I wanted to evoke Taphthartharath, there would be little help indeed from any but the Qabalistic system; for that spirit's precise forms and numbers are not to be found in any other.
   The converse, however, is not so true.  The Qabalah, properly understood, properly treated, is so universal that one can vamp up a ritual to suit almost "any name and form."  But in such a case one may expect to have to reinforce it by a certain amount of historical, literary, or philosophic study --- and research.