We are breathing air at high altitude in Isaiah chapter 40. The prophet is saying that God as an infinite and absolute Being is self-existent and independent of us, above all possibility of change. He must ever be what he has always been in his essence and attributes.
He is subject no process of development. His knowledge and power can never be greater or less. He can never be wiser holier or more righteous or more merciful than he has ever been and ever must be. He is no less immutable (unchanging) in his plans and purposes. Infinite in wisdom there can be no error in their conception; infinite in power there can be no failure in their accomplishment. In his changelessness however we must not think of Him as being immobile. He is perpetually active.
Some people climb the mountain Everest and others fly over it just once. Each of them attempts to tell us of the breath- taking experience of the 390 degree panoramic view. One ascent is not enough for us in our contemplation of God. We must climb often. Any ‘god’ of our own making is too small.