In the Septuagint, we find the word synagogue (gr. synagoges) mentioned many times while the IsraElites were in the desert. Just what type of building was this?
Well, it wasn’t a building at all. Actually, synagogue means a gathering or a calling together.
So, the entire nation of IsraEl was usually referred to as a synagogue. It wasn’t until many years later, after they had entered the Promised Land and possibly after their return from exile in Babylon, that the Jews started using local buildings for worship.
And that’s when we first read of their referring to the buildings as synagogues.
Such gathering places were probably first used while they were in captivity in the Babylonian empire. For, many still wanted to continue their association and worship in this place where there was no sacred Temple. And the practice was likely carried over upon their return to their homeland during the years that God’s Temple was in ruins and being rebuilt.
We also find the word synagogue mentioned several times in the Christian books. In almost every case, it refers to the Jewish (not Christian) meeting places or groups.
However, there is one instance where the word could be speaking a Christian meeting place, James 2:2.
Yet, even this instance (though commonly mistranslated and misunderstood) could possibly be speaking of a Judaic meeting place of worship, since James seems to have addressed his letter to the diaspora (scattered Jews), rather than to Christian congregations (see James 1:1).
Although synagogue originally meant a gathering of God’s people, people later later used it describe the buildings in which they met. However, during the 1st century CE, when the international language was Greek, Christians started calling their gatherings (and later their buildings) ecclesias, or in English, churches.
For more information, see the commentary, Congregation, Synagogue, or Called Ones.