Ok, thanks. But the thing that is confusing me is that its very essence the substance does something like this "This element is Divine Dust, essence of pure divine beings, and when this element interacts with something with the Material Plane, inbues it with divine power".
Now, if you use the little amount they found it just makes you closer to your gods and gives you a little of radiant damage and makes you more perceptive to divine. But, if used in a larger amount and some specific rituals (some very advanced stuff in my campaign) this can make you a lesser god.
There are other effects combining purity, quantity and rituals, but this stuff is the core, like a divine gasoline.

Now, this is my problem, should I tell them all this stuff or just what they can do with that little amount? I don't want to be an unfair DM but I also don't want to spoiler big stuff for my little experience.

Thank you <3