Eric

In the verse 2nd Thess 2:2 From a commentary The oldest manuscripts read, "day of the Lord."

2nd Thess 2:2 that you not be quickly shaken from your composure or be disturbed either by a spirit or a message or a letter as if from us, to the effect that the day of the Lord has come.
New American Standard Bible © 1995 Lockman Foundation

So 2:3 should be the Day of the Lord, instead of Day of Christ.

So let me reword your verse

"Let no man deceive you by any means:

for that day [of the Lord] shall not come,

except there come a falling away first,

and that man of sin be revealed, the

son of perdition;

Who opposeth and exalteth himself above

all that is called God, or that is worshipped;

so that he as God sitteth in the temple of

God, shewing himself that he is God."

- 2 Thessalonians 2: 3-4

:-) I know Its really the same thing. Jesus is Lord

GOD BLESS