Good question!!!
The word "Church" comes from the Greek word "ekklçsia"
It is actually a compounding of two words 'ek' meaning "out
of"
and "kaleo" meaning "to call"
Put together it means 'to call out of' This is the verb meaning.
But the word church is a noun. Hence, it's noun meaning derived
from the verb meaning is the 'called out ones'
Hence, if you ever read in the Bible something like: "the church
which is in Corinth or the church which is in Galatia". It simply
means "the called out ones which is in Corinth.............the
called out ones which is in Galatia......."
God is calling [through His gospel, 2 thessalonians 2:14] all
people all over the world to repent and trust in the Lord Jesus
Christ. Anyone who positively responds to His call will be added to
the ones who have responded to the call..... the Church...he will
become one of the called out ones.