God lets the people know that God is God and no other. In those times as in our time there were many gods competing for the allegiance of the people. To this day people tote around their idols and pray to gods who cannot save them. That is, your god is whatever or whomever you turn to and put your trust in.
Most people have a god, it is just a matter of who or what that god is.
This text is that of an early Christian hymn. A hymn to the mystery of the crucified savior. The one who was exalted by being lifted up on an instrument of death, the cross. In fact the exultation of Christ and the emptying of Christ on the cross are paradoxically simultaneous events. They form two sides of the same coin.