Three years . . . three years of following Jesus, listening to His teachings, watching His ministry. Three years and it all comes down to this: "But what about YOU? Who do YOU say that I am?" (emphasis mine). C.S. Lewis, of Narnia fame, once wrote that Jesus' question leaves us with three possibilities:
Jesus is a liar, a man whose word cannot be trusted when He declares "I and the Father are one" (John 10:30) or "I am the Living Bread" (John 6) or "I am the Good Shepherd" (John 10)
Jesus is a lunatic, a man who is stark raving mad with delusions of grandeur. Again, His word cannot be trusted.
Jesus is Lord, a man who really is the Son of God, God incarnate, who came to die for our sins and thereby restore us into relationship with God.
In a moment of divine insight, perhaps inspired by Caesarea Philippi's ancient connections to the god Pan, Simon Peter is bold enough to answer, "You are the Christ! The Son of the Living God!" (Matthew 16:16). Peter is not the first to confess Jesus as Lord. Others in the Gospels have done so. Usually, however, it is those who are ill or demon-possessed who recognize Jesus for Who He is. And, frequently, Jesus orders them to silence.
But not now, not here. In Matthew, Jesus focuses more and more on Jerusalem after this. He begins to teach His followers about His upcoming suffering and death. Jesus also begins to teach them about the true meaning of following in His footsteps. Given what the disciples will witness, Jesus' question is a matter of urgency.
Eventually, it all comes down to how you and I answer Jesus' question. No one else can answer it for us. At some point, you and I have to decide for our selves. If Jesus is a liar or a lunatic, then his life and ministry are meaningless. On the other hand, if He is Lord, then that makes all the difference in the world.