What does Matthew 16:20 mean?

Christian teachers in the modern world exhaust significant time, energy, and resources to declare the gospel. They loudly and persuasively tell all who will hear that Jesus is, in fact, the Christ and the Son of the living God. Peter and the other apostles will spend the remainder of their lives after the resurrection of Jesus travelling far and wide to declare that Jesus is the way of salvation for all who believe.

In this moment, however, Jesus forbids them from telling anyone directly that He is the Christ. Jesus is not unsure whether He will fulfill His mission as the Savior. Nor is Jesus is trying to keep people from knowing who He is. He has publicly displayed all the promised signs of the Messiah and taught as the Messiah. Many have acknowledged His identity (Matthew 9:27; 12:23; 15:22).

So why should the disciples be told not broadcast far and wide exactly who Jesus is? Jesus is sensitive to the weaknesses of the people. If enough became convinced that He was the Messiah—before His prophesied death and resurrection (John 12:32–34)—they would attempt to start a revolution against Rome, to make Him king of Israel (John 6:15). That would be based on a misunderstanding about what the Messiah had come to do on earth. He does not want that.

For now, Jesus seems most interested in allowing Israel's religious leaders and the people to decide for themselves who they will say that He is, based on His displays of God's power and His teaching. The floodgates of evangelism will open when the time is right (Acts 1:8).