Q. When Jesus said, “Upon this rock I will build my church” (Mt 16:18), is that the first time in the Bible the word “church” is used? If so, then how did people know what that word was if they had never heard it before?
A. Here’s a reply from TCA columnist Father Ray Ryland, Ph.D., J.D:
The Old Testament uses two words to designate the entire people of Israel as a religious community. The Septuagint, the Greek translation of the Old Testament made in the centuries before Christ, translates these words as ecclesia and synagoge. We translate them as “church” and “synagogue.”
The sacred writers of the New Testament clearly distinguished them, applying the term ecclesia (which translated the Hebrew term qahal) only to the community of Christian believers.
The new and uniquely Christian meaning of the term ecclesia (literally, “those called out”) reflects the fact that the Church is the kingdom of the Messiah. Through the Hebrew prophets God promised that His Messiah would establish a kingdom, with these basic characteristics:
It would have a new sacrificial system (see Ps 109:4; Mal 1:11; Jer 33:20-21).
It would be a kingdom possessing divine revelation (see Jer 31:31-34; Zec 8:3).
It would be governed by authority coming directly from the Messiah (Ez 34:23; 37:24-28; Jer 18:6).
When Peter confessed that Jesus is the Messiah (see Mt 16:16), Jesus was obviously delighted: “Blessed are you Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father” (Mt 16:17).
Then Jesus said, in effect: “You know I am the Messiah, so you know from Scripture [the Old Testament] that I have a kingdom. And you know what kind of kingdom it is. So I now put you in charge of that kingdom, as its earthly head.”
Immediately, the word “church” (ecclesia in the Greek New Testament, which no doubt translates the Aramaic qahal that Jesus would have used in speech) would have a world of meaning for those who came to know Jesus as the Messiah. So, as Matthew 18:18 tells us, Jesus could use the term with His apostles soon after, confident they knew He was designating the messianic community.