When Adam sinned and fell from grace a number of things happened.
FIRST - Adam became captive to a fallen sin nature and his fellowship with God was broken.
SECOND - The earth, man's home, was cursed because of man's sin. Rom. 8:22,23
THIRD - Satan became, by the permissive will of God, the god of this world. 2 Cor. 4:4 Lu. 4:5-6
Since that time Christ has come to redeem man and creation. We who know Christ as our savior, have been redeemed, but that redemption has not yet been applied to our bodies nor to the earth. Rom. 8:21
The book of Revelation deals with the redemption of.....ONE - A multitude of men and women. TWO - Israel. THREE - The earth itself.
In Rev. 5:1 We see the title deed to the earth. Rev. 5:2 The search begins for one to take the title deed and reclaim the earth from the usurper. Rev. 5:3-4 We see sorrow that the redemption of Christ is not being applied. Rev. 5:5 The redeemer is identified. Rev. 5:7 Chrit takes the title deed to the earth out of the hand of God.
Now in chapter 6, He begins to open the 7 seals of the title deed and begins to redeem the earth.
Also remember that Rev.6 begins the tribulation period on earth. Our Lord divides this 7 year period into two 3 1/2 year periods. He calls the first half the "Beginning of Sorrows". The second half He calls the "Great Tribulation" or "The Day of Jacobs Trouble," because in that period of time the antichrist will focus upon destroying Israel.
The whole 7 year period is marked by a rising intensity of the wrath of God being poured out upon the population of the world. It is also characterised by the hardening of the hearts of multitudes against God.
The whole 7 year period is characterised by the outpouring of God's wrath, not just the last 3 1/2 years.
Notice three things that indicate that the first 6 seal judgments are the wrath of God.
FIRST - They come directly from the hand of Christ to the earth. (Rev. 5:6-7 the scroll that contains the six seal judgments is now in the hands of Christ.) Rev. 6:1 It is the Lord Jesus Christ himself who holds the scroll and opens the seal judgments and casts them one by one upon the earth!
SECOND - The judgments contain the wrath of God.
Seal no.1 The deceiver (antichrist) is a judgment from the Lord upon the world. 2 Thess. 2:9-12
Seal no.2 War and killing also comes from the hand of Christ, as He breaks the 2nd. seal and casts it upon the earth.
Seal no.3 Famine sweeping the whole world. This also comes from the hand of Christ. (CP. Amos 4:6-7)
Seal no.4 Death, this also comes from the hand of Christ.
Seal no.5 The hearts of men so hardened by Christ so that they kill the servants of Christ. 2 Thess. 2:11
Seal no.6 Earthquakes, the sun and the moon darkened. This can only come from the hand of Christ.
THIRD - The men who survive the 6 seal judgments, call them the wrath of the Lamb. Rev. 6:17
The wrath of God begins to be poured out upon the world at the very beginning of the tribulation period. You cannot say, it is not poured out until the second half of the tribulation period.
The church is promised to escape this outpouring of God's wrath, therefore the rapture must occur prior to the tribulation period. 1Thess. 5:9 "But God has not appointed us to wrath, but to obtain salvation by our Lord Jesus Christ"
The context of this verse is the wrath of the tribulation period. Also Rev. 3:10