The verse, “You are My witnesses…and I am God”] is boldly interpreted by our sages:
“When you are My witnesses, then I am God; when you are not My witnesses, then I, as it were, am not God.”
Our sages give sharp expression to the special relationship between God and the Jewish People, to our stature and eternal role.
The Jews are “God’s witnesses,” and their existence is testimony before all of mankind to the existence of God.
The very fact that the Jewish People exists is an enduring demonstration of God’s kingship in the world.
–Rabbi Adin Steinsaltz