"The Powers of Thought"

He who is convinced and persevering
does a constructive work
...

There is one thing that you have to understand once and for all in respect to spiritual work, and that is that it involves matter of such extreme subtlety that it cannot be investigated by ordinary methods. The work we do on the spiritual level is just as real as that which we do on the physical plane.

When you work on the spiritual plane to edify something, set in motion forces and waves or bring light to the minds of human beings, your work is no less real than when you chop firewood or make soup on the physical plane. The only reason you cannot see what you do is that it is a different kind of matter. Actually though, when someone really lives on the spiritual plane, he does not need to touch or see its realities in the same way as he sees those of the physical world. It is enough for him to sense that they are there. With time, however, they can also materialize on the physical plane.

If you don't know these laws and you keep expecting immediate results from your spiritual work, you may easily become discouraged, and then you may destroy what you had already accomplished, for this very subtle matter is extremely pliant and easy to mould and, depending on whether he is convinced and persevering or not, man's work can be constructive or destructive. Often, in fact, he does a lot of constructive work but never brings anything to completion because he destroys it again almost at once. But inevitably, sooner or later, there will be a physical materialization.

Actually, if you question the Initiates, they will tell you that everything you see on earth is simply the materialization of etheric elements which have reached this degree of physical density. If you have sufficient faith and patience, therefore, all the things you wish for will also be condensed on the physical plane.