23 Now when He was in Jerusalem at the Passover, during the feast, many believed in His name when they saw the signs which He did.
Verses 23-25 are a unit. These verses are an argument about the nature of belief. This section corrects false ideas about the character of belief. This pericope bridges unbelief to belief found in John 3:1-15.
“Now” indicates a new thought and paragraph.
when He was in Jerusalem at the Passover,
The present scene was in the precincts of Jerusalem.
during the feast,
Jesus was in Jerusalem for both Passover and the Feast of Unleavened Bread that immediately followed Passover.
many believed in His name
The belief here is not genuine. People were superficially impressed by what Jesus did. They may have believed that He was a mere prophet. It was both a phony and shallow faith. Though they believed in Him, He did not believe in them (next verse). Their belief was spurious because it rested on an illusion. They would follow Jesus only so long as He was a wonder worker.
when they saw the signs which He did.
Those that “believed” saw “signs” (plural) that Jesus did. These signs were not the kind of sign that Jesus actually did; these were signs of their own making (Jn 12:39-40; 16:4). Their signs were probably magical indications of their delusional thinking. Their belief was an entirely different belief than what Jesus expected (note next verse). Jesus did not perform His second sign until John 4:54.
There is an acceptable belief and an unacceptable belief.
There is both authentic and unauthentic belief. Not all faith is saving faith (Jn 6:26). Magical belief and belief of people’s own making are not authentic belief. We see this in evangelical churches today. Many non-Christians in churches think that they believe properly.
Seeing and believing signs of themselves do not create saving faith. The Holy Spirit must convict the person supernaturally to believe. People can believe in what Jesus did without trusting His work on the cross to save their souls. There is a difference between assent to the spectacular and appropriation of its reality. People can be led astray by their astonishment and wonder. Belief in miracles is not necessarily belief in the person and work of Christ.
Jesus does not want followers unless they clearly know what is involved in following Him. He did not cash in on His popularity. He expected His followers to know what they were doing and believing.