Coming WW3 - 4th Seal
Beginning of 4th Seal
Out of these 3 mains killers of the 4th Seal or Period of the Beginning of Sorrows, I believe World War 3 will be the sign of the start. As soon as Israel and/or Egypt attack Iran, Iran will retaliate and will swiftly conquer it's neighbouring enemies and Jerusalem - a distinct sign of World War 3 for the sake of Christians.
If Christians still refuse to repent of their sins and heresies, then it will be too late for them. God will judge them using World War 3 or the new deadly pestilences (contagious as Omicron but deadly as Ebola with 20-50% mortality). This war will last for at least 6 months for the hundreds of millions of people to be starved to death.
For every one killed, at least 2 or 3 others will be affected. Fearless Christians will pick them up from the streets of death, to care, nurse and feed them in their own homes. When the unbelievers witness the power of God manifested through His disciples in healing the wounded and the sick, feeding thousands of starving people, their hearts will turn to God and be saved.
Dan 11:33 And those of the people who understand shall instruct many; yet for many days they shall fall by sword and flame, by captivity and plundering.
The Holy Spirit will help new converts to be discipled within weeks. Just like the Apostles at Pentecost, they too will be anointed to preach the gospel, understand and teach the truth in His words, and healing of the sick and needy after prayers, etc.
They will start then new home-cells to serve the affected communities. By the end of World War 3, there will be millions upon millions of these anointed home-cells discipling new converts.
The excitement of answered prayers and seeing miracles will increase the faith of all believers (both old and new) to overcome the coming Great Tribulation or Wrath of Satan (5th Seal) and then to be counted worthy to be the bride of the Lamb at Rapture (6th Seal).
Former Rain - Pentecost
At Pentecost 2000 years ago, the outpouring of the Holy Spirit with the sign of tongues of fire above the disciples' heads and the gift of tongues, was classified as the former rain where thousands upon thousands were saved.
Latter Rain (before Rapture)
Act 2:16-19 But this is what was spoken by the prophet Joel: 'And it shall come to pass in the last days, says God, that I will pour out of My Spirit on all flesh; your sons and your daughters shall prophesy, your young men shall see visions, your old men shall dream dreams. And on My menservants and on My maidservants I will pour out My Spirit in those days; and they shall prophesy. I will show wonders in heaven above and signs in the earth beneath: Blood and fire and vapor of smoke. The sun shall be turned into darkness, and the moon into blood, before the coming of the great and awesome day of the Lord (Rapture).
Before Rapture will be the great outpouring of the Holy Spirit (latter rain). With its many great signs and wonders, these will convince many. Dreams and visions (just like to the Roman Centurion) given to the religious and devout non-believers (Jews, Muslims, Hindus, Buddhists, Taoists, etc) will help them find salvation in Christ Jesus. During this 4th Seal, millions upon millions will be saved.