This song proclaims the one unique reality of God that I find the most fascinating. It is His eternality. I can sort of fathom the eternal nature of God... in a way. When I think about my own soul continuing after death, I have no problem accepting that, even though I cannot really know it until it happens. There is a part of the soul that instinctively believes that it lives on.
But the eternality of God is vastly different. I can accept entering life as a baby and living, then entering eternal life after death in this world. But God was never born. He always is. From everlasting past to an everlasting future He (present tense) IS God. That is where my mind starts grasping at and losing the threads of the thoughts about God's self-existence. I can run the time arrow forward from the present and sort of grasp an eternal future. But to do so while simultaneously running back in time FOREVER... whew! The mental exercise is amazingly mind-blowing! Theology gets psychodelic.
God's constant existence is unique. I believe it and I hold to it. It is revealed by Him for us to believe and to know. And in the hands of the great I Am (the always present One), my future is secure. The universe had its beginning in the word of God. A universe that is so big that we cannot fathom all of it was really just one of God's thoughts. Yet God always is. The very elements of the physical heavens and earth will one day be burned up and even remade. But God just... is... the unchanging, constant, consistent, loving Creator and Controller of forever past and present.