1: ἐκκλησία
(Strong's #1577 — Noun Feminine — ekklesia — ek-klay-see'-ah )

from ek, "out of," and klesis, "a calling" (kaleo, "to call"), was used among the Greeks of a body of citizens "gathered" to discuss the affairs of state, Acts 19:39 . In the Sept. it is used to designate the "gathering" of Israel, summoned for any definite purpose, or a "gathering" regarded as representative of the whole nation. In Acts 7:38 it is used of Israel; in 19:32,41, of a riotous mob. It has two applications to companies of Christians, (a) to the whole company of the redeemed throughout the present era, the company of which Christ said, "I will build My Church," Matthew 16:18 , and which is further described as "the Church which is His Body," Ephesians 1:22; 5:23 , (b) in the singular number (e.g., Matthew 18:17 , RV marg., "congregation"), to a company consisting of professed believers, e.g., Acts 20:28; 1—Corinthians 1:2; Galatians 1:13; 1—Thessalonians 1:1; 2—Thessalonians 1:1; 1—Timothy 3:5 , and in the plural, with reference to churches in a district.

Acts 9:31Acts 8:1Romans 16:23CHURCH.
2: πανήγυρις
(Strong's #3831 — Noun Feminine — paneguris — pan-ay'-goo-ris )

from pan, "all," and agora, "any kind of assembly," denoted, among the Greeks, an assembly of the people in contrast to the council of national leaders, or a "gathering" of the people in honor of a god, or for some public festival, such as the Olympic games. The word is used in Hebrews 12:23 , coupled with the word "church," as applied to all believers who form the body of Christ.

3: πλῆθος
(Strong's #4128 — Noun Neuter — plethos — play'-thos )

"a multitude, the whole number," is translated "assembly" in Acts 23:7 , RV. See BUNDLE , COMPANY , MULTITUDE.

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