What does John 2:20 mean?
The temple was massive and beautiful. Solomon had built a gorgeous structure (1 Kings 6), which was unfortunately raided by the Egyptians a few decades later (2 Chronicles 12:1–5). Israel eventually rebuilt it, as described in the books of Ezra and Nehemiah. The Rome-appointed king, Herod, was upgrading this "second temple" at the time Jesus began His ministry. It was the center of Jewish worship, and entirely necessary for proper sacrifices to God. When asked to perform a miracle to justify His disruption of trade inside the temple grounds (John 2:13–18), Jesus claimed He can rebuild a destroyed temple in three days (John 2:19).In this gospel, "the Jews" are usually the scribes, Pharisees, and other religious leaders. They would have been offended at the idea that something so important could be so easily rebuilt. However, Jesus was predicting His own death and resurrection. This statement will be used against Jesus both during His trials (Matthew 26:61) and as heckling when He is crucified (Matthew 27:40). In AD 70, the Roman Empire would completely obliterate the temple and the Jewish sacrificial system would be erased (Mark 13:2; Hebrews 8:13).
John 2:13–23 describes Jesus driving corrupt businessmen from the temple. His wrath is not because of selling sacrifices, itself, but rather the greedy focus on money with no regard to serving God. Jesus is never depicted as out of control, but His anger is clear. It's likely that this is an early temple cleansing, and the other gospels record a second, separate incident. Jesus' right to act this way is challenged by the authorities. In typical Hebrew style, they demand a miraculous sign. Jesus instead predicts His own death and resurrection. This passage contrasts with the quiet, joyous miracle at the wedding.
Jesus attends a wedding where He performs His first miracle: turning water into wine. This symbolizes a transformation of human rituals into divine sacrifice. Few people are even aware that a miracle has occurred. Jesus then drives crooked businessmen out of the temple, scolding them for turning a sacred area into a crass marketplace.