"Earthquake" is mentioned seven times
in the Book of Revelation.
Just as we are not talking about a literal city Babylon being destroyed
(Revelation 16:18) or a literal "great city" which is "spiritually
[figuratively, Strong's #4153] called Sodom and Egypt"
(Revelation
11:13,19)similarly the "earthquake" that destroys false Christendom is not
literal.
An earthquake is an upheaval from beneath the earth. "Earth"
represents organized society. An upheaval from underneath stable society would be a
revolution of the people. False Christendom's destruction will
come from within—underneath.