Does Hell exist? 1:8-9

"Be not soon shaken in mind ... by letter as from us."
What letter is being referred to here? Is it 1 Thessalonians? If so, then should Christians not read it to avoid being "skaken in mind?" 2:2

If Paul wrote this letter (and many scholars think he didn't), then he is changing his mind (since writing 1 Thessalonians) about the timing of the Christ's return. The day of the Lord is no longer at hand. In fact it's nowhere near. Many things must happen first: there will be a great "falling away", a "man of sin" will be reveled, and Satan will show off his power by doing all kinds of signs and wonders. 2:2-9

Jehovah's Witnesses use these verses to justify disfellowshipping anyone who disagrees with the Watchtower's teachings. 3:6, 14

Does the bible condemn gambling? 3:10

Although 2 Thessalonians claims to have been written by Paul, many scholars think it was a forgery. 1:1, 3:17