Is God Unfair? Are there people who will have not heard the gospel by the time of judgment?
At the outset of the coming Tribulation, 2 witnesses appear. And for 3.5 years they preach the gospel on the worldwide stage in the midst of the 6 seals being opened, and the 7th seal and the first 6 trumpets. Finally they are killed, resurrected, and taken into heaven. Revelation 11.
The end-times fills in even more understanding of God’s character, power, and mercy. The end-times exposes Satan and his plan for humanity explicitly.