There are two kinds of thought: one kind acts on, affects, moves, changes what it is about, the other kind does not. The kind of thought that makes change is about something invisible, the kind that does not is about something visible.
When we act within ourselves we can't see what we are doing. We make our bodies move, we remember, we imagine.
When we act on the visible world, our power over it comes from knowing its rules. Using our invisible power to move our body, we rearrange the order of visible things in a way our discoveries tell us will make happen again what we want to happen.
Using memory, imagination, and command over our bodies, we have a sense of stability, that we know what we are doing. But whether things outside us will keep to their rules, or change from one moment to the next, we know nothing. We have no power over, we aren't in any continuous relation to these things. We use the power of our thought to move our bodies only to set in motion a machine in which the parts use their own power on each other.
We know what we can and cannot do within ourselves by a lifetime of experience and practice. We don't know what the world can and cannot do, only what it has done so far. What would surprise you more: that the stars in the universe, previously thought to be stable in their movements in relation to each other, suddenly are discovered to be distancing themselves from each other at an ever increasing rate? Or that you suddenly discover you could fly through the air? The first has recently been confirmed, and no one really cares. But the second....
The rules of the visible world are approximations, which though constantly improving in accuracy and practicality, nonetheless never offer the kind of certainly we have when we move our body or call upon a memory. The invisible kind of things just happen. Their certainty comes from the very fact of there being no intermediary parts with unclear relation to each other. As long as the body is properly functioning the mind's orders will be followed. It is all clear. There is nothing in the sequence of command and execution to fall into decay or malfunction, nothing to be corrected by future reformulation.
We know what we can do with our bodies and thoughts. But our bodies know hardly anything about what they can do with other bodies. They are attracted or repelled, incompletely and irregularly. The things we see in the world blunder around with each other like our bodies do with other bodies.
The more we think about it the more unreal things in the world become. We are powerless to move them with our thoughts. But our thoughts, when they are at their highest perfection, can take us to sight of a world without parts, the way the world looks when we love. The parts are still there. It's just that they have no significance. Which is to say there is nothing we can do with those parts, we have now everything we want.