1. There are two purposes for the Lord's return to this earth:
And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also. (John 14)
The first purpose of the Lord's return, is to resurrect and receive His church unto Himself in the air. (1 Thess 4)
Then shall the trees of the wood sing out at the presence of the LORD, because he cometh to judge the earth. (1 Chr 16)
Arise, O God, judge the earth: for thou shalt inherit all nations. (Ps 82)
Then the Lord will judge all the earth and inherit the nations, beginning with His tribulation and wrath of plagues and terrible signs from above.
2. There are two kinds of great tribulation on the earth:
Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the kingdom of God. (Acts 14)
The tribulation and wrath of the devil and man is against the saints of God, which began with Cain troubling and then slaying righteous Abel.
God allows that tribulation to purify and sanctify His people unto Himself. (Dan 12:9-10)
But unto them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath, Tribulation and anguish, upon every soul of man that doeth evil, of the Jew first, and also of the Gentile. (Rom 2)
God sends His own tribulation with wrath, to punish them that hate Him, and who also make trouble and war with His people on earth.
Great tribulation and wrath of the devil and man, is promised to God's people for their own good, in being prepared to meet Him at His coming, whether from the grave, or remaining alive on earth.
Great tribulation and wrath of God, is promised by God to the wicked for their punishment and anguish, as just reward for their evil deeds against Him and His saints.
For God hath not appointed us to wrath, but to obtain salvation by our Lord Jesus Christ.
We are appointed unto the tribulation and wrath of the world, but not unto that of God, which the righteous escaped by the ark, and will be by the first resurrection of the dead in Christ, and alive in Christ on earth.
3. The last days of much tribulation upon the people of God, began with Jesus building His church on earth after His resurrection.
God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds. (Heb 1)
These last days of tribulation upon the saints, also began with many antichrist beasts coming to trouble, confuse, seduce, and possibly destroy the churches of God. (John 2)
These last days of the saints on earth, will end with the rise of the last beast and false prophet's tribulation upon the church over all the earth. It will end by their resurrection and ascension into the air, which will be in the sight of all God's enemies. (Rev 11:11-12)
In that hour is when the great tribulation, wrath, and indignation of God will begin upon all the earth, in terrible signs and wonders (Rev 10:1), like that visited upon Egypt. (Deut 4)
And the same hour was there a great earthquake, and the tenth part of the city fell, and in the earthquake were slain of men seven thousand: and the remnant were affrighted, and gave glory to the God of heaven. (Rev 11)
My Conclusion of Scripture:
The great tribulation and wrath of the devil and man upon all the earth, has been so far for over six thousand years, but at the end of the saints living on earth, there will be a flood-like unexpected and swift tribulation and wrath of God over all the earth:
Esaias also crieth concerning Israel, Though the number of the children of Israel be as the sand of the sea, a remnant shall be saved: For he will finish the work, and cut it short in righteousness: because a short work will the Lord make upon the earth. (Rom 9)
The great tribulation and wrath of God upon His enemies, has been at times and places such as the flood of Noah, and of Egypt, and outside Jerusalem's walls, but will be over all the earth at one quick and swift time as the flood, to prepare the way for His return upon the earth to judge all remaining.
The great tribulation and wrath of the world upon the righteous, has been long due to the mercy of God:
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
But the great tribulation and wrath of God, that is a long-time coming, will be short and quick over all the earth.
The distinct dividing line between the tribulation and wrath of the devil on the earth, and that of the Lord from the air, is the resurrection and ascension of all the saints of God.
The rapture of the church is both post-tribulation by the devil, and pre-tribulation by God, by dividing them in a moment and twinkling of the eye.