Now we will examine the Greek word Ecclesia in greater detail:
THE SEVEN ASSEMBLIES AS A WHOLE (i. 11).
(Taken from Bullinger, E.W. (2011-08-21). The Apocalypse or “The Day of The Lord”: Commentary on Revelation , Trumpet Press. Kindle Edition).
We must here, at the outset, remove the greatest source of all the misunderstandings which have arisen with regard to these seven “churches.” The fact of their being called “churches” has naturally led commentators and students of this book to infer that it is the Church of God, or at any rate the historic Christian Church, which is meant. As a first step toward removing this great evil, let us note at once that the word (…) (ecclesia), rendered “church,” is by no means limited to the restricted sense which is thus forced upon it.
Ecclesia means simply an Assembly: any assembly of people who are called out (for that is the etymological meaning of the word) from other people. Hence, it is used of the whole nation of Israel as distinct from other nations. The Greek word Ecclesia occurs seventy-five times in the Septuagint Translation of the Old Testament, and is used as the rendering of five different Hebrew words. As it is used to represent one of these, seventy times, we need not concern ourselves with the other four words. This Hebrew word is (…) (Cahal), from which we have our English word call. It means to call together, to assemble, or gather together, and is used of any assembly gathered together for any purpose. This Hebrew word Cahal occurs 123 times, and is rendered: “congregation ,” 86 times; “assembly,” 17; “company,” 17; and “multitude,” 3 times: but is never rendered “church.”
Its first occurrence is in Gen. xxviii. 3 – “that thou mayest be a multitude (margin, assembly) of people,” i.e ., a called-out people. That is what Israel was, a people called out and assembled from all other peoples. In Gen. xlix. 6 we read – “O my soul, come not thou into their secret ( Council or Senate); Unto their assembly (cahal), mine honour, be not thou united.” Here the word cahal is used, not of all Israel as called out from the nations, but of the assembly of those called out of form the Tribal Assembly (or Council) of the tribes of Simeon and Levi. Then, it is used of the worshippers, or those called out from Israel, and assembled before the Tabernacle and Temple, and in this sense is usually rendered “congregation.” This is the meaning of the word in Ps. xxii. 22: “In the midst of the congregation will I praise Thee;” and verse 25: “My praise shall be of Thee in the great congregation.”
We ought to use the word Ecclesia in the sense in which it is here used; and not, surely, in the newer and special sense which it acquired, and in which it is used, in the Epistles. In the Pauline Epistles we read nothing about an “angel” as having to do with the churches of God which Paul planted. When the word Ecclesia, in the Apocalypse is rendered “Church,” and the word “Synagogue” in Rev. ii. 9 and iii. 9, is interpreted of the church, it is playing fast and loose with the “words which the Holy Ghost speaketh,” and which He (God) has employed, not only for His revelation, but for our instructions. We hold that the Apocalypse contains a record (by vision and prophecy) of the events which shall happen “hereafter” in the Day of the Lord; that the whole book is concerned with the Jew, the Gentile, and the Earth, but not with the Church of God, or with Christendom; or with the latter only so far as the present corruption of Christianity ……after the Church, the Body of Christ, shall have been removed.