In the days of Jesus, the Jewish people believed in a form of incarnation. They did not believe that God could become a man, but that heaven and earth connected at the Temple in Jerusalem. God, for the Jewish person, dwelled in some sense in the temple. The temple was seen as the central incarnational symbol of Jewish life.
The Incarnation of the Temple
This is one of the primary reasons that the teachings and actions of Jesus were so controversial. In many different ways and at many different times, Jesus indicated that He was the new temple; that in Him people could receive forgiveness from sins, access to God, and restoration from exile. When people believe that God is in the temple, imagine what a shock it would have been for Jesus to announce that the Temple would be destroyed (John 2:19-21).
But as shocking as it was to predict the destruction of the Temple in Jerusalem, John indicates that Jesus was actually talking about His own body! We tend to think that this would soften the blow of such words for Jewish people at the time, but the opposite is actually true.