HALFWAY through our time in the wilderness of Lent, we read of the Israelites’ impatience during their own desert pilgrimage. It is one of many episodes on that forty-year jour­ney in which they are faithless and impetuous (Numbers 11 and Exodus 32 are the most striking examples). Not only had the Hebrews been enslaved in body in Egypt: the idolatry of the Pharaoh’s empire had gone deep into their souls. It took four decades of purgation in the desert for their hearts and minds to be renewed.

In our passage, the people’s sins lead to a plague of poisonous serpents. According to the Venerable Bede, this punishment “provides an excellent instance of how one may recognise from the results of an ex­­ternal scourge what a great calam­ity a person might suffer inwardly by murmuring”. It is not simply that their lack of faith displeases the Lord. Their faithless and impetuous grumbling is spiritually “calamitous”, because it obstructs God’s saving work.

This spiritual struggle is echoed in the interior life of every Christian. As St Jerome warns, we, too, need to be “on our guard” lest we be “bitten by the serpents”. Like the Israelites, we need to make a decisive break with the values of this world’s empires: “We have left Egypt; what have we to do with the food of Egypt? We who have bread from heaven, why do we go in search of worldly foods?”

When God’s people look back nostalgically to the slavery of Egypt, when they bridle at the length and discomfort of the journey, they close their hearts to the risk-filled life of faith. The same is true of each of us.

In Numbers 21, the sin (impatience and murmuring) and the punishment (poisonous serpents) seem like two separate things. We might be forgiven for thinking that God is like a human parent who has reached the end of his tether — responding to the impatience of the people with his own exasperated rage.

This Sunday’s Gospel explains the true relationship between our sin and God’s judgement, with the unambiguous declaration by Jesus that “God did not send the Son into the world to condemn the world, but in order that the world might be saved through him.” God’s “judgement” is not a separate act, but con­sists in the very fact that “the light has come into the world, and people loved darkness rather than light because their deeds were evil.”

The words of Jesus are part of a dialogue with Nicodemus, who, we are told earlier in the chapter, has come to him “by night”. In explaining his saving mission, Jesus refers back to our Old Testament lesson. Just as God’s people were saved by gazing on a bronze serpent, so Jesus will be “lifted up”, so that “whoever believes in him may have eternal life.”

In gazing on the bronze serpent, the Israelites saw both an image of their “calamity” and a sign of God’s mercy. In the “lifting up” of Jesus, each of these aspects is intensified. We see both the appalling extent of our human “calamity” (our death-dealing rebellion against God) and the wideness of God’s mercy (as he takes that violence upon himself, returning only love).

This act of divine mercy still requires a response of faith. If we remain “fixed behind the walls of our certitude and power . . . we will remain closed in fear, violence, and the powers of darkness with us” (Jean Vanier, in Drawn into the Mystery of Jesus by the Gospel of John). When we come to the light, by contrast, our deeds are “done in the truth”.

It is this process of transformation which Paul describes in the epistle. In a passage that echoes the words of Jesus, the apostle writes that the God who is “rich in mercy” has saved us by his grace, “out of the great love with which he loved us”. By this act, and our response of faith, we are “created in Christ Jesus for good works”.

Our good actions are not the re­sult of any programme of anxious self-improvement. What the Lord requires of us, as of his people in the desert, is a patient faith­fulness, so that our hearts can be renewed to receive — and to spread — the great love with which he loves us.