Simon Peter replied, “You are the Christ, the Son of the living God.” And Jesus answered him, “Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven. And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it. (Matthew 16:16″18,

Jesus was referring to Peter’s declaration: “You are the Christ, the Son of the living God.” This confession of faith is the rock upon which the church is built, and just like Peter, everyone who confesses Jesus Christ as Lord is a part of the church.

Church Definition in the New Testament
The word “church” as rendered in the New Testament comes from the Greek term ekklesia which is formed from two Greek words meaning “an assembly” and “to call out” or “called out ones.” This means the New Testament church is a body of believers who have been called out from the world by God to live as his people under the authority of Jesus Christ:

God has put all things under the authority of Christ and has made him head over all things for the benefit of the church.

And the church is his body; it is made full and complete by Christ, who fills all things everywhere with himself. (Ephesians 1:22″23