[1] https://plato.stanford.edu/entries/pythagoreanism/ [2] https://en.wikipedia.org/wiki/Pythia
With regards to Pythagoreanism, Pythagoras himself thought of mathematics in religious ways. From the entry on Pythagoras (https://plato.stanford.edu/entries/pythagoras/) in the SEP:
> The cosmos of the acusmata, however, clearly shows a belief in a world structured according to mathematics, and some of the evidence for this belief may have been drawn from genuine mathematical truths such as those embodied in the “Pythagorean” theorem and the relation of whole number ratios to musical concords.
There are numerous sections throughout both of these entries that discuss Pythagoras, mathematics, and religion. Plato too is another fruitful avenue, if you wanted to explore that further.