HERE with Be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand. (v.2)
The author, who claims to be Paul (but probably wasn't), contradicts what the real Paul said in 1 Thessalonians (4:13-17) -- that Jesus would be returning soon, within Paul's lifetime.
This "Paul" says to ignore another letter that he supposedly wrote.
What letter is being referred to here? Is it 1 Thessalonians? If so, then should Christians not read it to avoid being "shaken in mind?"
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 revealed, and Satan will show off his power by doing all kinds of signs and wonders.
Is the Day of the Lord at hand?
See Bart D. Ehrman, The New Testament: A Historical Introlduction to the Early Christian Writings, 3rd ed. (2004), chap.23
-Remember ye not, that, when I was yet with you, I told you these things? (v.5)
No, they don't remember. Because the real Paul told them exactly the opposite in 1 Thessalonians.
-Satan with all power and signs and lying wonders. (v.9)
Satan, not God, is all-powerful.
Can only God work wonders?
-God shall send them strong delusion, that they should believe a lie: That they all might be damned. (vv.11-12)
God will cause us to believe lies so that he can damn us to hell.
Do humans have free will?
Does God lie?
Does God want some people to go to hell?
Who forces non-believers to disbelieve?
-God hath from the beginning chosen you to salvation. (v.13)
God selects those who are to be saved (or damned) "from the beginning." It therefore makes no difference how good, kind, honest, or loving we may be; if God hasn't chosen us, we will be damned.
Do humans have free will?
What the Bible says about determinism and free will
Don't be fooled - Jesus isn't coming soon
1 Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him,
2 That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
Don't be fooled by those who claim to have received a letter from us saying that Jesus has already returned. [1]
3 Let 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;
Don't let anyone deceive you.
That day won't come until many stop believing,
and a man of sin, the son of perdition, is revealed,
4 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.
who will exalt himself above God,
and will be worshiped as God in the temple.
5 Remember ye not, that, when I was yet with you, I told you these things?
Don't you remember that I told you these things? [2]
6 And now ye know what withholdeth that he might be revealed in his time.
7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
Now you know that he'll be revealed in his time.
His iniquity is already at work,
but someone is holding him back.
And he won't be revealed until
that person is taken out of the way.
8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
When the wicked one appears,
the Lord will kill him by breathing on him.
9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved.
He will come after the all-powerful Satan appears [3]
with all his signs and wonders.
God will send then strong delusion
(so they believe a lie and be damned)
11 And for this cause God shall send them strong delusion, that they should believe a lie:
God will send them strong delusion,
that they believe a lie,
12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
so that they all will be damned. [4]
13 But we are bound to give thanks always to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth:
But we thank God for you,
because God chose you for salvation from the beginning. [5]
14 Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ.
He called you to believe our gospel,
and thereby obtain the glory of Jesus.
15 Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle.
So hold on to the traditions that you've been taught,
by word, or from our letter.
16 Now our Lord Jesus Christ himself, and God, even our Father, which hath loved us, and hath given us everlasting consolation and good hope through grace,
17 Comfort your hearts, and stablish you in every good word and work.