Our universe is like a thought wave - invisible state or quantum wave function spread over space and time. "Not a wave of matter" - but wave in what? In a universal ocean - an ocean of pure potentiality - a unified field - superstring field that of which we are all made of.
In this ocean our thoughts travel, each thought make a ripple and a difference.
Everyday when we are thinking we make a ripple in this sea of energy we call the universe.
The principle of cause and effect explains that there is a cause for every effect, and an effect for every cause.
You get back what you put out. When you put a negative out, you will get one back. Also, when you put a positive out you will get a positive back.