The full verse is:
"Created from dust,
You came and You lived among us.
You took on our frame, You walked in our pain.
And now You're taking us higher"
The origin of the phrase is the King James Bible, Genesis 3:19:
In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return.
The phrase was then taken up in the Anglican Book of Common Prayer, when, during a funeral service, the priest offers the burial rites:
Forasmuch as it hath pleased Almighty God of his great mercy to take unto himself the soul of our dear brother here departed, we therefore commit his body to the ground; earth to earth, ashes to ashes, dust to dust; in sure and certain hope of the Resurrection to eternal life, through our Lord Jesus Christ; who shall change our vile body, that it may be like unto his glorious body, according to the mighty working, whereby he is able to subdue all things to himself.
The song is indeed about God. Specifically, it is about God incarnate as Jesus, come down to Earth in the form of Man, knowing that he would sacrifice himself an then lead us to Heaven. The later verses make this quite clear.