Don't think that God's "still small voice" is weak because it is still or small. This same voice created everything, all matter, energy and time and organized it all into the magnificent universe and the marvelous living chemistry of cellular life. How else would he have done it? He is not matter but spirit.
John 4:24 (NKJV)
God is Spirit
John 6:63 (NKJV)
It is the Spirit who gives life; the flesh profits nothing. The words that I speak to you are spirit, and they are life.
Words are God's power and we have been made in His image and so when he gave us the ability to speak, He gave us a bit of that same power.
Proverbs 15:4 (NKJV)
A wholesome tongue is a tree of life, But perverseness in it breaks the spirit.
My words can harm another person in terrible ways but my words can also build another person up.
If I invent anything or imagine a computer program that will perform some helpful task and then I take those thoughts and express them in words organized in a careful way then I have created something from shear thought and words. No matter how much material I had to push around or how much energy I had to expend, the fact is that the end product would not have exited apart from the original thought. When I speak it is the expression of the mind. In this sense all expressions of my mind are my "words" just as all expressions of God's mind are the "words" of God.
The ancient philosophers spoke of the "prime mover." It was an argument for the existence of God. The fact that things are in motion means that there has been a chain of events in which things are moved by a mover which itself was moved by a prior mover and so on. To avoid an infinite regression, there must be an unmoved mover or the first mover, itself unmoved; this prime mover is God. But how did He do it? He did not touch the thing because that implies a physical action of the mover contacting the moved. Since God is spirit, there is no contact. It was idea, thought, the mind of God, in essence the word of God which did the moving.
Willard speaks of our ability to have a thought and an immediate action. I am thinking as I type this sentence but I am not aware at all of how my fingers tap the keyboard. They just do; I think and they move.
Psalm 33:9 (NKJV)
For He spoke, and it was done; He commanded, and it stood fast.