The New Testament Gospel of Matthew contains the two recordings of Jesus speaking the word church or, more specifically, ekklesia. In both chapters 16 and 18, Matthew records Jesus' use of the term which He used in reference to people.
R. T. France wrote . . .
When Jesus speaks of "building his church," the foundation rock and the verb "build" are the solid images on which the metaphor relies, but the word "church" does not contribute to the physical imagery. The Greek term ekklesia never denotes a physical structure in the NT, but always a community of people. (p. 623)While the word church has come to be used primarily in reference to a structure that holds people, the most accurate usage refers to the reverse of that. A church is a gathered people who are built on the structured foundation of Jesus Christ.
The word ekklesia is a combination of two Greek words each meaning "out" and "called." The ekklesia (the church), therefore, consists of those who are called out by Jesus to follow Him.
We have no plans to lengthen the name and, therefore, also no plans to widen the size of our location's sign. So passers-by and "drivers-in" may still think the last of the three words on our sign refers to the building. I hope, however, that when they enter our building, they experience church as the church welcomes them to join them in this God-given, Jesus-honoring, and Spirit-led journey.
"Here is the building. Here is the steeple. Open the building and here is the church."
France, R.T. The Gospel of Matthew - The New International Commentary on the New Testament. Grand Rapids: Eerdmans, 2007.