2 Thes 2:3
That day shall not come, except there come
a falling away first...

The falling away will be a great apostasy that will
take place in the Church during the persecutions and
sufferings of the coming tribulation. Many Christians
will forsake the Lord to avoid martyrdom or to show
their anger at Him for letting them suffer.

Matt 24:10
And then shall many be offended, and shall betray
one another, and shall hate one another.

The Greek word for falling away is "apostasia,"
apostasy. It means a willful denial of the Lord. It's
used one other time in the Bible, in Acts 21:21, where
it’s translated "forsake."

Vine’s Expository Dictionary says apostasia means a
defection, revolt, apostasy, and is used in the NT of
religious apostasy.

The terrible irony will be that many Christians who
believe that God has promised them a "catching up"
before the tribulation, will be among those who will
deny the Lord and become part of the great
"falling away."

John
6:66
From that time many of his disciples went back,
and walked no more with him.

1 Tim 4:1
In the latter times some shall depart from the faith...

Luke 18:8
When the Son of man cometh, shall he find faith
on the earth?

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Neither the Liddell & Scott Intermediate Lexicon
nor the Liddell-Scott-Jones Lexicon of Classical
Greek show people departing a physical place as
one of the meanings of apostasis.

Similarly, Paul didn't use apostasis when he
referred to people departing a physical place.

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