What does John 11:42 mean?

Jesus' words in this part of His prayer express the primary purpose of miracles: demonstrating divine approval of some message or idea. Jesus has arrived when Lazarus' death is absolutely beyond dispute (John 11:39), and He now speaks in front of a crowd of witnesses (John 11:31, 35–37). By making this declaration, Jesus is giving context to the upcoming miracle (John 11:43–44).

The gospel of John uses the term "signs" when describing Jesus' miracles (John 2:11; 4:54; 6:14). What happens in the next verse is the seventh and most spectacular of these signs. As with all of Jesus' supernatural acts, the purpose is to prove His divine nature (John 20:30–31). Some of Christ's miracles were relatively private, such as turning the water into wine in Cana—few people knew Jesus was involved. Some were public, but abrupt, such as giving sight to the blind man (John 9:1–7).

People respond to God's miraculous signs in varied ways. This is much the same way they respond to the mundane physical signs we see on streets and in buildings. When printed signs offer warnings or guidance, some accept what is said. Others notice, but don't take the message seriously. Some ignore it entirely, thinking it does not apply to them. Others deliberately ignore warning posters because they don't like the restriction. Jesus makes this miracle extremely obvious, and as a result, the reaction from His most hateful critics is extreme as well. Instead of accepting the meaning of the miracle, the religious leaders of Jerusalem will seek death for both Jesus and Lazarus (John 11:53; 12:10–11).