When Jesus asked His disciples, "Who do people say that the Son of Man is?" it was not because He was trying to obtain information. Jesus could read the thoughts of people and did so on many occasions. Rather, He wanted to see if His disciples were getting it.
They told him, "Some say John the Baptist, some say Elijah, and others say Jeremiah or one of the other prophets" (Matthew 16:14).
Then He asked, "But who do you say I am?" (verse 15).
So Peter went out on a limb. He said, "You are the Messiah, the Son of the living God" (verse 16). Peter nailed it.
So Jesus told him, "You are blessed, Simon son of John, because my Father in Heaven has revealed this to you. You did not learn this from any human being. Now I say to you that you are Peter (which means 'rock'), and upon this rock I will build my church, and all the powers of Hell will not conquer it" (verse 17-18).
To clarify, Jesus was not saying He would build the church on Simon Peter. The word "Peter" comes from the Greek word that means a part of a rock or a stone. The phrase "upon this rock" contains a different word altogether, which means a massive rock.
Jesus was building the church on what Peter said. The church is built on Christ. As the apostle Paul said, "For no one can lay any foundation other than the one we already have—Jesus Christ" (1 Corinthians 3:11).
I hope your life is built on Christ. If you have built your life on a church, that is the wrong foundation. If you have built your spiritual life on a person, that is a faulty foundation. Build your life on Christ himself.