Abstractions, at least ones that survive over long periods of time, like the use of numbers, or like human spirituality, tend to contain within them a large collection of truths. Large collections of truths are what I mean by a greater reality, because they are not reality, they are abstracted ideas that are based on reality, but serve a greater purpose.
Something being more real than the reality in front of us is not a new idea, idealism was introduced by Plato 2,400 years ago suggesting that true reality lies in the world of perfect ideas, otherwise put, a reality more real than the physical world.
Like I said though, all of this is my interpretations of readings and based on my own years of thought and experience.