What year did Christ institute the Church?

We can have a pretty good idea. For example, it is generally agreed among the Fathers and early Christian writers that Jesus was born around 2-3 B.C. and that Jesus would have begun his ministry in the same year St. John the Baptist began his, in about A.D. 29 (the fifteenth year of the reign of Tiberius; see Luke 3:1).

From there, it appears St. Matthew focused much of his Gospel on Christ’s first year of ministry. You see this by the fact that he focuses on the genealogy (chapter 1); the Magi and flight into and return from Egypt (chapter 2); the preaching of John the Baptist and baptism of Jesus (chapter 3); the temptation of Jesus and his inaugural announcement in the synagogue that he is the Messiah, his beginning to call the apostles, and his first teaching and preaching, which leads to the Sermon on the Mount done very early in his ministry, which covers chapters five through eight.

Then, in chapter nine, we know it is still early because he calls St. Matthew. It isn’t until chapter ten that he gets all twelve apostles together and gives them power to minister. In chapter eleven, St. John the Baptist is still alive, and Jesus finds out about the death of John in chapter fourteen, which means it must have just happened, and we know from Mark and Luke this happened early in Jesus’ ministry. Then, the text of Matthew has things happening rapidly up to Matthew 16:18.

I say all that to say that it is not a stretch to say the promise of the keys was early in Jesus’ ministry. Matthew is not known for telescoping like Luke. So, if Jesus began his ministry in A.D. 29, this probably takes place around A.D. 30—or 31 at the latest.