Matthew 16: Opposing forces unite against Jesus; Peter declares Jesus' divinity, then rebukes him.

The Pharisees and the Sadducees were lifelong enemies, but when Jesus came along, they became united in their efforts to discredit and destroy Him.
They demand a 'heavenly' sign, implying that all of His previous signs could be Satanic counterfeits. Jesus responds by giving them a lesson in reading the weather.
Jesus warns the disciples to beware of their false and contaminated teaching, using the word "leaven" (which any Jew should recognize as a metaphor for sin or corruption.
However, the disciples don't get it, and Jesus once again has to explain Himself to His dense followers.
Jesus takes the disciples to Caesarea Philippi, a region filled with many pagan temples and false gods. With this backdrop, Jesus asks them, "Who do people say that I am?"
Peter speaks for the group, saying Jesus is the Messiah, the Son of God. Jesus uses this as the foundation for a new thing called a 'church'.
He then explains that following Him will require they forsake themselves and 'take up their cross'. To them, a cross was just a cruel instrument of torture and execution. (It didn't have the sweet, religious connotations of today.)
He then confirms that, when He uses the phrase "Son of Man" to refer to Himself, He is using it in the context of Daniel where it refers to the divine human sent from heaven that is worthy of all worship.