Apostasia–apostasy or departure; error or truth?

There is some controversy regarding this word in 2 Th 2:3. The following are displays how several translations or versions has it:
for unless the apostasy comes first, NASU

for unless the falling away comes first, NKJV

for unless the rebellion comes first, ESV

for except the falling away come first, ASV

for unless there come a revolt first, Douay-Rheims

for it will not be unless the departure comes first, WEB

except there come a falling away first, KJV
Apostasia has been translated as a falling away, a departure, a revolt and a rebellion. It was transliterated as apostasy, which is not a translation at all. This transliteration has evolved into revolt and rebellion, as well. My vote is on departure, but if apostasy were correct, what would it look like?

Noun, The abandonment or renunciation of a religious or political belief.
Synonyms: defection – recreancy

There are 18 prepositions in the New Testament, one of which is apo. Apo governs only the Genitive case and denotes motion away from the surface of an object, as a line drawn from the circumference. It is used as motion away from a place. For example:
Mt. 3:16: And Jesus, when he was baptized, went up straightway “out of” (apo) the water:
Mt 8:1 When he was come down “from” (apo) the mountain,
Ac 15:38
But Paul thought not good to take him with them, who departed “from” (apo) them

Mt. 19:4 and Acts 20:18 mark the distance which separates the 2 places or the interval of time between the 2 places.
Apo also marks the origin or source whence anything comes such as birth descent, residence:
Mt 2:1
there came wise men “from” the east
Mt 15:1
which were “of” Jerusalem, saying,
Ac 10:23
certain brethren “from” Joppa

Apo may also be used of deliverance or passing away from any state or condition:
Mt 14:2 he is risen “from” the dead  (From E. W. Bullinger.)

With all this biblical evidence you should be able to see that apo governs physical displacement, not a mental change in attitude. Bullinger uses a circle to represent how the preposition apo acts: a line drawn away from its edge. This circle represents the earth and the line drawn away from its surface is our departure to Heaven. There is no evidence whatsoever of a defection away from truth or God in any way, shape or form.

If not, what?