"The sixth chapter of Isaiah has a deep and important lesson for every one of God’s workmen.
Study it with humility and earnest prayer.
Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me. Isaiah 6:8
The first and second
chapters of Ezekiel should also be carefully 
studied. The wheels within
wheels represented in this symbol was confusion to the finite eye. But a
hand of infinite wisdom was revealed amid the wheels. Perfect order is
brought out of the confusion. Every wheel works in its right place, in
perfect harmony with every other part of the machinery.
The appearance of the wheels and their work was like unto the color of a beryl: and they four had one likeness: and their appearance and their work was as it were a wheel in the middle of a wheel. Ezekiel 1:6. "
E.G.W.