2 Thessalonians 2:3Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
This is the only time in Scripture that the words, ‘man of sin’ is mentioned, so it is the son of perdition.
This son of perdition is an entire group of people who have turned away from Jesus or fell back to sin and law.
I proved this with all the verses that mention perdition on another thread.
so there is not 1 man of sin or 1 son of perdition. It is a full church or kingdom of what we call backsliders.