we request that you people do not become shaken up in your mind, nor alarmed, either by a spirit [i.e., by some prophetic prediction], or by a report, or by a letter supposedly from us, that the day of the Lord [i.e., when Jesus returns] has already come.

Do not allow anyone to deceive you in any way, for it will not occur until the rebellion comes first and the man of lawlessness becomes evident. [Note: This "rebellion" refers to a significant falling away from the teaching and practice of true Christianity (See I Tim. 4:1), characterized by the rise of an authoritarian religious leader]. This man is doomed to be destroyed