The serpents can be seen to be a judgment upon Israel that reveals and symbolizes their sin. The souls of the Israelites have been poisoned by the deceiver so that they do not trust in the goodness of God and his provision and plan for them. The people who committed themselves to the covenant with God instead adulterously follow after Egypt and the way of life it represents—a life where their immediate desires are fed yet they are enslaved, a life that falls short of what God intends for them in the promised land.
The serpents’ venom, like bitter water, has entered into the people and caused bitter pain, showing that they have indeed gone astray. As with Adam and Eve, the venom of doubt about the words, ways, and goodness of God had taken hold of Israel and was leading to their “spiritual death.” In response to the serpents, Israel is moved to confession: “We have sinned by speaking against the Lord and against you; pray to the Lord to take away the serpents from us” (Num. 21:7). As a result of this confession, God does relent. He does not simply forgive them of their sin and heal them outright, but rather commands Moses to construct a “fiery serpent” and set it on a nas (“standard”).
The bronze serpent represents to the people all that the fiery serpents represent. In it they can see the sufferings of their journey. But in it they also can see the judgment of God about them. Like the raising of a battle standard, this action ironically represents who the people are truly following: the serpent, rather than God. This people, this generation, have rejected God and his ways, and are following instead the ways of the serpent, the envious desire for power, the lust for the easy comforts of Egypt that makes them turn back from entering the land. It is a fitting symbol for all the rebellions of the people.
But the raised serpent is more than a sign of judgment. It is also a sign of God’s victory over the serpent. Like the head of an enemy placed on the tip of a spear and shown to the people, the serpent lifted up shows that God is more powerful than the serpent. God is able to cure the physical effects of the serpents’ poison.
By offering to the people this symbol of victory over the serpent, it also becomes a symbol of God’s compassion and desire to heal them and to do them good. It is a symbol that God did not send Moses to his people in Egypt to condemn them, but to save them and bring them life.