This is a question with a long answer and subject to those who will answer.
I can only share with you what I know to be true. That being said, this is how I will answer your question:
The laws of metaphysics are an expansion on the laws of physics; God's laws, which, can never be broken. They work whether you believe in them or not. Should you decide for any reason that you do not believe in gravity, you will not fall off the face of the earth. For centuries most people thought that the world was flat, but no one fell over an edge. We all work within those laws whether we are aware of it or not.
Now as to the tarot and oracles in general, if one did not believe that there were some part of himself that were able to communicate with a higher intelligence or that there were such a thing as a higher intelligence or that communication were possible, they probably would never try. Not really, anyway.
Where you are now is at the beginning of faith. Willing to open yourself up to a possibility with no basis of belief one way or another, and skepticism is a good thing at this stage.
The greatest evidence we have that a higher intelligence exists is by the order of the universe from the microcosm to the macrocosm and it is with this principle that the cards work. At any given moment our energy and the energies with which we interact affect everything we do. Have you ever had to organize things and worked at it and had to leave it and come back a day or two later to finish and thought, "What was I thinking of " and rearranged it all because it made no sense on the second day?
Artists experience this a lot. If I leave a painting too long and come back to it, it seems all wrong. The person I was when I started the painting no longer exists, my reason for wanting to paint it in the first place might elude me.
Anyway, that is how the arranging of the Tarot cards and also the choice of the cards to read play into it.
There are a million names for the higher intelligence of the universe the one I use is Spirit. I know that Spirit is trying to communicate with us all the time the most commonly known way probably is through our dreaming.
When we cooperate and are willing to learn the language of Spirit, symbols, feelings, intuition we find a vast body of knowledge at our disposal. Really the only difference between card readers and people who do not read the cards is that we took the time to learn the language. We are truly interpreters.
Ask Spirit to help you and it will. During a meditation years ago I was told that when we say we can't we make the angels cry. We must be willing to try, That is all.
