You are blurring issues. Lets judge properly!
1. Paul's torture
God tests His people. Allows the wicked to test them. He only has this opportunity to properly test us. See what we are made of. He will use it. But He will not test us beyond our ability 1 Cor 10:13. This is God testing ''His people''. e is with us in our suffering Heb 13:5.
Judgement = No evil from God
2. Tribulation
The tribulation shows us a mix of God's instant destruction and then plagues at increasing severities.
If you read Revelations you will see that after every plague it says ''they repented not'' Rev 16:10. Pointing to the fact that God is 'trying' to get them to repent. If we look at those on Egypt. They started off light and got worse. Ten plagues. Ending up in them all losing their first born. Why ten plagues? It points to God trying to get the people to repent and change their rebellion to Him. It points to His ''last ditched'' attempt. This we know is the purpose for the tribulation. His people are raptured. Those on earth require a sifting process.
Judgement = No evil from God
Who brought up judgment being evil from God?
Those left behind die by the billions (2/3 of all on earth) by some of those "last ditch" efforts. No, the tribulation plagues were not designed to "sift" people or award them reprieve if they repented. They didn't repent when it was beneficial to repent. God promised before He would avenge His children. On the upside, Christians are spared, and a third of those left behind survive.
God has always wanted all vengeance for wrongs, so is just to pour out His wrath on the abusers of God's people, forcing them to suffer in the flesh for months of misery, then die. The third (why they survive I don't know) will repopulate earth over the next thousand years, then be faced with a last ditch effort by Satan to deceive and to kill, then be cast into the lake of fire forever with all who followed him, men and angels. What of God having the angel release those creatures like that? Righteous. No evil in Him!
Revelation 16:5-7 (KJV)
5 And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus.
6 For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy.
7 And I heard another out of the altar say, Even so, Lord God Almighty, true and righteous
are thy judgments.
The basis for that vengeance:
Romans 3:5 (KJV)
5 But if our unrighteousness commend the righteousness of God, what shall we say?
Is God unrighteous who taketh vengeance? (I speak as a man)
Romans 12:19 (KJV)
19 Dearly beloved, avenge not yourselves, but
rather give place unto wrath: for it is written, Vengeance
is mine; I will repay, saith the Lord.
2 Thessalonians 1:5-10 (KJV)
5
Which is a manifest token of the righteous judgment of God, that ye may be counted worthy of the kingdom of God, for which ye also suffer:
6 Seeing
it is a righteous thing with God to recompense tribulation to them that trouble you;
7 And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels,
8
In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:
9 Who shall be punished with everlasting destruction from the presence of the Lord, and from the glory of his power;
10 When he shall come to be glorified in his saints, and to be admired in all them that believe (because our testimony among you was believed) in that day.
Hebrews 10:30 (KJV)
30 For we know him that hath said, Vengeance
belongeth unto me, I will recompense, saith the Lord. And again, The Lord shall judge his people.