At first, 1 Samuel 4-7 doesn’t seem to exhibition of power.
Instead, we see Israel losing a battle and the Ark of the Covenant (God’s representation on earth) being stolen by a foreign power. However, the context shows that Israel treated the Ark as if it were an idol. The way people use idols as the way to create blessing in their lives.
Israel treated God like an idol, as a tool, as a weapon to be used by their hands.
Through this story we see that God will not allow Himself to be used. He is the One in control. The first exhibition of power was God literally destroying the god Dagon in the Philistine’s temple and then sending a plague of tumors. This led to the Philistine lords sending the Ark away by cart to Israel. We see that for the next 20 years Israel, “…lamented after the Lord.” (1 Samuel 7:2)
Their salvation did not come until they listened to the words of Samuel, “…direct your heart to the Lord and serve him only, and he will deliver you out of the hand of the Philistines.'” (1 Samuel 7:3) Once the people put their idols away, God rescued them in the next attack from the Philistines, defeating the whole army by a “mighty sound.” (1 Samuel 7:10)