Paul was writing about an individual we have come to label as the “antichrist”. One day a real, live, flesh and blood individual will emerge, not only to conquer the world, but get the world thinking that he is the true savior. He will be the embodiment of evil and, in fact, will be “possessed” by Satan himself.
How could the world fall for something or someone so evil? Paul said that it would happen because the people will become detached from truth, starting with the truth about salvation.
Have you noticed how difficult it is for our culture to decide on what is true? We live in a world where people are satisfied to call something “true” simply because they “feel” it’s true, regardless of any actual empirical basis. We want some notion about a person we despise to be true simply because we don’t like that person, and not whether the idea is based in fact.
Here’s a piece of truth. There was an actual, historical person named Jesus. Records of His words and life continue to be proven accurate. He claimed to be God. He claimed to die for our sins. He rose from the dead. Will you trust the truth?