In the book of Matthew chapter 16:18, Jesus said “and I say also unto thee, that thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it." Jesus prophesied that he would build his church and that prophecy was fulfilled on 33 A.D.
In the book of Acts 2:1-47, verse 47 states, “Praising God, and having favor with all the people. And the Lord added to the church daily, such as should be saved.” If the Lord added to the church daily, then, that implies that the church must be in existence.
The Bible also teaches that the church is Jesus' body “And hath put all things under his feet, and gave him to be the head over all things to the church, which is his body, the fullness of him that filleth all in all.” (Ephesians 1:22-23).
Since the church is Jesus' body, then how many bodies does Jesus have? “There is one body, and one Spirit, even as ye are called in one hope of your calling." ( Ephesians 4:4) The church of Christ is that same church that Jesus prophesied about and that began in Acts chapter 2.
". . . the churches of Christ greet you." Romans 16:16