When we talk about how God proves himself as one and only true God, which happens during the time of Moses, this really enlightens us.
This reveals the question that whether there is only one true God, which this question has already been asked thousands of years ago, so long before our generation. The story of Israelite deliverance that is from Egypt stands as so undeniable testimony of God's supremacy over all.
In Egypt there are so many gods, the gods of the sun, the night, the earth, and even death, so yet, one by one, the temple, the law, show that he alone has power over all creation. When the night turned into blood, when darkness covered the land, and when our firstborn and all the Egyptians died, it was clear that no other power could stand against God.
This proof came when he parted the Red Sea and acted that no human spirit or idol could ever be. Brother Eli remind us that God's existence and authority are not subject to the doubt of human or modern questioning.
This already shown to us that his power, love, and justice is in history. What this reminds us is for humanity to keep acknowledging who should trust in his word and serve him faithfully as the one and only true God in our lives.