Do not be decieved by anyone, here is your study.

Here let your Holy Spirit speak to you on the falling away first must happen before JESUS comes, also what the trumpet means, ask God to reveal to you by His Holy Spirit and He will. Study to show yourself approved by GOD. I ask you LORD to reveal to all who seek to know will find out what it means, in JESUS name Amen.
2 Thessalonians​​ - from the KJV.
Chapter 2
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. 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; 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.

5 Remember ye not, that, when I was yet with you, I told you these things? 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. 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: 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. 11 And for this cause God shall send them strong delusion, that they should believe a lie: 12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
13 But we are bound to give thanks alway 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: 14 Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ. 15 Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle. 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.

Chapter 3
1 Finally, brethren, pray for us, that the word of the Lord may have free course, and be glorified, even as it is with you:
Exodus 19:13 There shall not an hand touch it, but he shall surely be stoned, or shot through; whether it be beast or man, it shall not live: when the trumpet soundeth long, they shall come up to the mount.
Exodus 19:16 ¶ And it came to pass on the third day in the morning, that there were thunders and lightnings, and a thick cloud upon the mount, and the voice of the trumpet exceeding loud; so that all the people that was in the camp trembled.
Exodus 19:19 And when the voice of the trumpet sounded long, and waxed louder and louder, Moses spake, and God answered him by a voice.
Exodus 20:18 ¶ And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking: and when the people saw it, they removed, and stood afar off.
Leviticus 25:9 Then shalt thou cause the trumpet of the jubile to sound on the tenth day of the seventh month, in the day of atonement shall ye make the trumpet sound throughout all your land.
Numbers 10:4 And if they blow but with one trumpet, then the princes, which are heads of the thousands of Israel, shall gather themselves unto thee.
Joshua 6:5 And it shall come to pass, that when they make a long blast with the ram's horn, and when ye hear the sound of the trumpet, all the people shall shout with a great shout; and the wall of the city shall fall down flat, and the people shall ascend up every man straight before him.
Joshua 6:20 So the people shouted when the priests blew with the trumpets: and it came to pass, when the people heard the sound of the trumpet, and the people shouted with a great shout, that the wall fell down flat, so that the people went up into the city, every man straight before him, and they took the city.
Judges 3:27 And it came to pass, when he was come, that he blew a trumpet in the mountain of Ephraim, and the children of Israel went down with him from the mount, and he before them.
Judges 6:34 But the Spirit of the LORD came upon Gideon, and he blew a trumpet; and Abi–ezer was gathered after him.
Judges 7:16 And he divided the three hundred men into three companies, and he put a trumpet in every man's hand, with empty pitchers, and lamps within the pitchers.
Judges 7:18 When I blow with a trumpet, I and all that are with me, then blow ye the trumpets also on every side of all the camp, and say, The sword of the LORD, and of Gideon.
1 Samuel 13:3 And Jonathan smote the garrison of the Philistines that was in Geba, and the Philistines heard of it. And Saul blew the trumpet throughout all the land, saying, Let the Hebrews hear.
2 Samuel 2:28 So Joab blew a trumpet, and all the people stood still, and pursued after Israel no more, neither fought they any more.
2 Samuel 6:15 So David and all the house of Israel brought up the ark of the LORD with shouting, and with the sound of the trumpet.
2 Samuel 15:10 ¶ But Absalom sent spies throughout all the tribes of Israel, saying, As soon as ye hear the sound of the trumpet, then ye shall say, Absalom reigneth in Hebron.
2 Samuel 18:16 And Joab blew the trumpet, and the people returned from pursuing after Israel: for Joab held back the people.
2 Samuel 20:1 And there happened to be there a man of Belial, whose name was Sheba, the son of Bichri, a Benjamite: and he blew a trumpet, and said, We have no part in David, neither have we inheritance in the son of Jesse: every man to his tents, O Israel.
2 Samuel 20:22 Then the woman went unto all the people in her wisdom. And they cut off the head of Sheba the son of Bichri, and cast it out to Joab. And he blew a trumpet, and they retired from the city, every man to his tent. And Joab returned to Jerusalem unto the king.
1 Kings 1:34 And let Zadok the priest and Nathan the prophet anoint him there king over Israel: and blow ye with the trumpet, and say, God save king Solomon.
1 Kings 1:39 And Zadok the priest took an horn of oil out of the tabernacle, and anointed Solomon. And they blew the trumpet; and all the people said, God save king Solomon.
1 Kings 1:41 ¶ And Adonijah and all the guests that were with him heard it as they had made an end of eating. And when Joab heard the sound of the trumpet, he said, Wherefore is this noise of the city being in an uproar?
Nehemiah 4:18 For the builders, every one had his sword girded by his side, and so builded. And he that sounded the trumpet was by me.
Nehemiah 4:20 In what place therefore ye hear the sound of the trumpet, resort ye thither unto us: our God shall fight for us.
Job 39:24 He swalloweth the ground with fierceness and rage: neither believeth he that it is the sound of the trumpet.
Psalms 47:5 God is gone up with a shout, the LORD with the sound of a trumpet.
Psalms 81:3 Blow up the trumpet in the new moon, in the time appointed, on our solemn feast day.
Psalms 150:3 Praise him with the sound of the trumpet: praise him with the psaltery and harp.
Isaiah 18:3 All ye inhabitants of the world, and dwellers on the earth, see ye, when he lifteth up an ensign on the mountains; and when he bloweth a trumpet, hear ye.
Isaiah 27:13 And it shall come to pass in that day, that the great trumpet shall be blown, and they shall come which were ready to perish in the land of Assyria, and the outcasts in the land of Egypt, and shall worship the LORD in the holy mount at Jerusalem.
Isaiah 58:1 Cry aloud, spare not, lift up thy voice like a trumpet, and shew my people their transgression, and the house of Jacob their sins.
Jeremiah 4:5 Declare ye in Judah, and publish in Jerusalem; and say, Blow ye the trumpet in the land: cry, gather together, and say, Assemble yourselves, and let us go into the defenced cities.
Jeremiah 4:19 ¶ My bowels, my bowels! I am pained at my very heart; my heart maketh a noise in me; I cannot hold my peace, because thou hast heard, O my soul, the sound of the trumpet, the alarm of war.
Jeremiah 4:21 How long shall I see the standard, and hear the sound of the trumpet?
Jeremiah 6:1 O ye children of Benjamin, gather yourselves to flee out of the midst of Jerusalem, and blow the trumpet in Tekoa, and set up a sign of fire in Beth–haccerem: for evil appeareth out of the north, and great destruction.
Jeremiah 6:17 Also I set watchmen over you, saying, Hearken to the sound of the trumpet. But they said, We will not hearken.
Jeremiah 42:14 Saying, No; but we will go into the land of Egypt, where we shall see no war, nor hear the sound of the trumpet, nor have hunger of bread; and there will we dwell:
Jeremiah 51:27 Set ye up a standard in the land, blow the trumpet among the nations, prepare the nations against her, call together against her the kingdoms of Ararat, Minni, and Ashchenaz; appoint a captain against her; cause the horses to come up as the rough caterpillers.
Ezekiel 7:14 They have blown the trumpet, even to make all ready; but none goeth to the battle: for my wrath is upon all the multitude thereof.
Ezekiel 33:3 If when he seeth the sword come upon the land, he blow the trumpet, and warn the people;
Ezekiel 33:4 Then whosoever heareth the sound of the trumpet, and taketh not warning; if the sword come, and take him away, his blood shall be upon his own head.
Ezekiel 33:5 He heard the sound of the trumpet, and took not warning; his blood shall be upon him. But he that taketh warning shall deliver his soul.
Ezekiel 33:6 But if the watchman see the sword come, and blow not the trumpet, and the people be not warned; if the sword come, and take any person from among them, he is taken away in his iniquity; but his blood will I require at the watchman's hand.
Hosea 5:8 Blow ye the cornet in Gibeah, and the trumpet in Ramah: cry aloud at Beth–aven, after thee, O Benjamin.
Hosea 8:1 Set the trumpet to thy mouth. He shall come as an eagle against the house of the LORD, because they have transgressed my covenant, and trespassed against my law.
Joel 2:1 Blow ye the trumpet in Zion, and sound an alarm in my holy mountain: let all the inhabitants of the land tremble: for the day of the LORD cometh, for it is nigh at hand;
Joel 2:15 ¶ Blow the trumpet in Zion, sanctify a fast, call a solemn assembly:
Amos 2:2 But I will send a fire upon Moab, and it shall devour the palaces of Kerioth: and Moab shall die with tumult, with shouting, and with the sound of the trumpet:
Amos 3:6 Shall a trumpet be blown in the city, and the people not be afraid? shall there be evil in a city, and the LORD hath not done it?
Zephaniah 1:16 A day of the trumpet and alarm against the fenced cities, and against the high towers.
Zechariah 9:14 And the LORD shall be seen over them, and his arrow shall go forth as the lightning: and the Lord GOD shall blow the trumpet, and shall go with whirlwinds of the south.
Matthew 6:2  Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward.
Matthew 24:31  And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
1 Corinthians 14:8 For if the trumpet give an uncertain sound, who shall prepare himself to the battle?
1 Corinthians 15:52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
Hebrews 12:19 And the sound of a trumpet, and the voice of words; which voice they that heard intreated that the word should not be spoken to them any more:
Revelation 1:10 I was in the Spirit on the Lord's day, and heard behind me a great voice, as of a trumpet,
Revelation 4:1 After this I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter.
Revelation 8:13 And I beheld, and heard an angel flying through the midst of heaven, saying with a loud voice, Woe, woe, woe, to the inhabiters of the earth by reason of the other voices of the trumpet of the three angels, which are yet to sound!
Revelation 9:14 Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates.