So I wanted my magic system to have spells based within different religions, each of which rooted in (but not limited to) the country of the race it corresponds too.
Dogfolk have their own spiritualist beliefs and spells that fit their style of worship to their deities, such as conjuring spirits and moonlit illusions or manipulating nature in some way.
I also wanted to give a way for religions to blend together and created the Church of the Collective Union, who believe all deities are real and your belief in them gives them power, allowing you to use different spells for worshiping multiple deities. to make a dynamic power system to reflect the personality of those who use it. However I seen how this could be abused, I knew I needed to a limit on what you can do within that system. So I made it so each religion has three core values. Then I also realized that most people would just join the collective for more freedom, so I decided to give "pure" religions kind of a bonus category of spells that is unlocked by mastering all three other cores.
The lizardfolk are strong people who believe their strength is what matters not their magic, so they use the magic they have to enhance the strength they have, they also have a strong culture of blacksmithing. Their cores are Steel, Fire, Power. They can manipulate metals and certain minerals. create and manipulate fire, and Power works as positive buffs to beef themselves up. If they master all three they can create simple firearms like muskets and cannons.
I like this system and I've enjoyed coming up with the Master Magics. However, I wanted to give the collective a way to play with their magic more. My first idea was going to allow them to make a pilgrimage to each of their core's holy sites to get a better understanding of each of their different values and how they can be used together better. Then I realized that "pure" religions could also do this. One of my friends suggested making a language for the magic, like words for shape, element, action, and religious spells are just preset sentences that are passed down due to their usefulness. I really liked that idea but each religion is from a different race that has their own ancestral language so do I go back and make the magic language an ancient language they all had in common at one point, or a totally different language that's like a "language of the gods". I've thought about this for a long time and my brain is just jelly at this point, I've hit a wall so I'm asking for advice or an alternative idea.
Edit when I say language as magic I mean kind of in a Skyrim dragon way I guess is the closest example I can think of. I don't mean just speaking and talking about fire makes fire. As for the church of the collective, they can only do three core values, so they aren't power grabbers and try to master every magic there is. They can study all the magics and religious history, but the god only lets them pick three core values to embody and practice to produce spells. I did find a good example of the shape element and action. Sword Art Online: Alicization had something close, it was basically using the games source code to program a function stating the size element and action of a magic object. like the spell fireball would be Fire Sphere Propell. Also, the gods are purposely ambiguous to make things easier on myself. Whether they are just stories made up to explain how the first magic users symbolically discovered how to use magic. If they actually gifted the ability magic to their followers. Or if they didn't exist, but then were manifested by the belief in them over time due to the magic. Magic is why this world exists its part of the physical planet, but somewhere along the way, humans learned how to use it to benefit them, and then found a way to make it easier through the gods whether it was just stories or gifts or beliefs that magic itself adopted from the widespread use of that idea. I think this is more realistic since there's that same debate about our own gods within our world. And for the church of the collective just believes all of these gods are real, kind of like modern pagans or witches, not 100% sure if they are still the same thing, but they believe all deities are real, and "work" with the ones that reach out to them, and some believe that you should stick to one branch of deities such as Norse or Greek gods, and others believe you should work with one type of deities like sun gods and goddesses of water gods and so forth. Its also slightly similar to Shinto where everything has a spirit or god and they should all be respected, as to how the gods would benefit from this rather than getting jealous, they would still have that person believing and respecting them, giving them power. someone's belief in something cannot be divided, you believe or you don't, being skeptical of something is still a sliver of belief and gives it power. so I don't think the collective is at all unrealistic and I've made it in a justified way that doesn't allow for god-like magic users to master every single core value, as some definite don't mesh together. You cant believe in healing the world and making it free of suffering while also believing in brute force and conquering your enemies. you can't believe music and sound is essential to life while also believing silence is the best way to solve a conflict. these cores have to understood and made a part of that person's soul and moral code in order to use it, being a part of the collective just means you think all of those values are valid and you can choose the values that best suit you.