All other things derive being – their ‘is-ness’ is secondary. But God did not derive His being from any other – His ‘is-ness’ is underived, original, eternal! He was, and is, and is to come, the eternal ‘I Am.’ Rather than concealing His identity, this Name reveals the deepest mystery of His being, and rocks our minds with the discovery that we cannot begin to fathom the mind and life of this eternal God.
Sinclair Ferguson