The London plague of 1665 is synopsized in the UK National Archives this way:
This was the worst outbreak of plague in England since the black death of 1348. London lost roughly 15% of its population. While 68,596 deaths were recorded in the city, the true number was probably over 100,000. Other parts of the country also suffered.This artwork depicts the general attitude during the height of the plague.
The earliest cases of disease occurred in the spring of 1665 in a parish outside the city walls called St Giles-in-the-Fields. The death rate began to rise during the hot summer months and peaked in September when 7,165 Londoners died in one week.
Current world population (estimate) - 7,321,593,981. That's 7 billion with a b.
Revelation 6:7-8 says,
When he opened the fourth seal, I heard the voice of the fourth living creature say, “Come!” And I looked, and behold, a pale horse! And its rider’s name was Death, and Hades followed him. And they were given authority over a fourth of the earth, to kill with sword and with famine and with pestilence and by wild beasts of the earth.
So in rapid order, 25% of the earth's people will die. A quarter of 7.3 billion people is 1,830,398,495 dead. That's 1.8 Billion dead. Remember the 2004 Banda Aceh Christmas day tsunami that killed 250,000 people? Bodies washing up everywhere? Multiply that by tens of thousands and millions and you have some idea of the deaths that will take place when the fourth seal is opened. It will happen fast, too. The entire Tribulation will only be as long as 7 years, and the Seal judgments are opened at the outset, so pretty quickly bodies will pile up in the streets.
So after a fourth of the population dies, we have 5,491,195,486 remaining on earth. That's 5.4 Billion people.
Revelation 9:18 says that another third will die quickly also, this time in the Trumpet Judgment. "By these three plagues a third of mankind was killed, by the fire and smoke and sulfur coming out of their mouths."
This means that a third of 5.4 billion people will die. That's another 1,812,094,510 billion dead. Billion with a B.
By now there are 3,679,100,976 people left. Of course there area great many fewer because countless numbers die in the wars, die or are killed due to violence because of no restraint on sin, and secondary causes like fires from unattended gas lines or cholera or starvation. So let's estimate another billion have died from all those causes. That leaves 2.6 billion people and that is only halfway through the Tribulation. We have gone from 7.3 billion people down to 2 billion- or less.
I suspect the death from sin will be much higher than we even can comprehend. The Holy Spirit will not be restraining sin at all. All men will be able to be as bad as they can be, moral depravity will be at highest levels ever. People will kill with impunity, for no reason, just to see you die. They will die from drugs and alcohol other bodily excesses, illness, starvation, and likely suicides. We know that the world will be used to looking at death with no problem, because by the time the Two Witnesses are killed their bodies are allowed to putrefy in the street for three and a half days while the entire world looks at them and dances in joy over their death. (Revelation 11:9-10)
3,642,493,005 or half the current population will for a fact die. All those bodies laying around is unimaginable. Here is one graphic that shows 1 Billion pennies. This is only 1 billion, remember, and they are pennies, very small, not human bodies.
Source
Jesus said that if he did not come back, ALL FLESH would die. (Matthew 24:22). When you try to imagine the numbers of corpses it become a horror, unimaginable and hopeless. Burials will not keep up. Every zombie/apocalypse/plague/outbreak/dystopian movie you ever watched won't even come close. The Left Behind movies were sanitized like meat under cellophane compared to the slaughterhouse the meat came from. The overriding feature of the Tribulation will be...blood.
The first angel blew his trumpet, and there followed hail and fire, mixed with blood, and these were thrown upon the earth. And a third of the earth was burned up, and a third of the trees were burned up, and all green grass was burned up. (Revelation 8:7)
And the winepress was trodden outside the city, and blood flowed from the winepress, as high as a horse’s bridle, for 1,600 stadia. (Revelation 14:20)
When the Lamb broke the fifth seal, I saw underneath the altar the souls of those who had been slain because of the word of God, and because of the testimony which they had maintained; and they cried out with a loud voice, saying, "How long, O Lord, holy and true, will You refrain from judging and avenging our blood on those who dwell on the earth?" (Revelation 6:9-10)
The second angel poured out his bowl into the sea, and it became like the blood of a corpse, and every living thing died that was in the sea. (Revelation 16:3)
And I saw the woman, drunk with the blood of the saints, the blood of the martyrs of Jesus. When I saw her, I marveled greatly. (Revelation 17:6)
I saw thrones on which were seated those who had been given authority to judge. And I saw the souls of those who had been beheaded because of their testimony about Jesus and because of the word of God. (Revelation 20:4)
People say that the Bible is a tale of two cities, Jerusalem and Babylon. We could say without stretching it that the Age of Grace is about the blood of Jesus- Holy blood. And the Tribulation is about the blood of sinners- Judgment blood.
So when I hear someone say "I'm a pantheist, it'll all pan out in the end," I know that person has no conception of the prophetic plan of God. They have no care for the billions of people who will die like animals under God's judgment. The deaths, the stench of death, the desensitization regarding death, it all will be on a scale the mind will not be able to comprehend.
Yet each one of those deaths represent a soul, made in the image of God. (Genesis 1:27)
Truly no man can ransom another,
or give to God the price of his life,
for the ransom of their life is costly
and can never suffice,
that he should live on forever
and never see the pit. (Psalm 49:7-9)
No person, regardless of his means, is able to escape death; it is inevitable. (Hebrews 9:27) This passage anticipates the second death of hell, (cf. Rev. 20-11:15), except those who by faith have repented of their sin and embraced the only adequate ransom, the one paid by the Lord Jesus Christ by His death on the cross. (cf. Matthew 20:28, 1 Peter 1:18-19). ~John MacArthur
Knowing we live in the Age of Grace and were saved in it should give us knee-weakening, heart stopping gratitude to Jesus. And knowing what is ahead for the world and its people should give us knee-weakening, heart stopping fear of God and His mighty power and Holy wrath. He is coming soon.
Be ready.
Live like you're ready.
Witness like it's your last day on earth, because it's could be- for you or for that person.