Nicodemus rightly understood that the miracles Jesus performed demonstrated that He had been sent by God (John 3:1–2). Lest Nicodemus think that his recognition of Jesus’ origin made him fully competent to judge spiritual things, however, our Lord directed the conversation with the Pharisee to expose how much Nicodemus had yet to understand. When Jesus told Nicodemus that he had to be born again, he did not understand our Savior, as we see in today’s passage (vv. 3–6).
According to Isaiah 52:1–12, the ancient Israelites could look forward to the day when they would be rescued from their exile in a foreign nation. At that point, the people would be cleansed of sin and renewed, Israel would take her rightful place at the head of the nations, and it would be evident to the world that the God of Israel reigns over all (see especially v. 7). Another way of saying this is that Isaiah looked forward to the day when the kingdom of God would come and all would be set right in the world.
Most first-century Jews believed they would automatically receive citizenship in this kingdom because they were progeny of Abraham (see, for instance, the confidence Jesus’ opponents placed in their being Abraham’s descendants; John 8:12–58). To hear that something more was needed to see and enter the coming kingdom was shocking indeed to many first-century Jews, particularly those known for their painstaking adherence to the law of Moses. As a Pharisee, Nicodemus belonged to this group of particularly scrupulous Jews, and that probably explains, at least partly, why Nicodemus misunderstood when he heard that even he needed to be born again. After all, Jesus’ words in today’s passage indicate that being born again is required of all who want to become citizens of God’s kingdom (John 3:3, 5).
That being born again refers to a spiritual change is evident from Jesus’ saying that to be born again is equivalent to being born of the Spirit (vv. 3, 5). The spiritual change required is no minor change but a complete transformation. The need to be born again indicates that one must be granted a brand-new nature. A new person, in essence, has to be created in place of the old. This refers to regeneration, the act whereby God changes us at the very root of our being so that we can believe. John Calvin comments, “By the phrase born again is expressed not the correction of one part, but the renovation of the whole nature.”