Everyone will worship something

“All inhabitants of the earth will worship the beast – all whose names have not been written in the book of life belonging to the Lamb that was slain from the creation of the world.” Revelation 13:8
Today it seems to be almost fashionable to be an atheist or agnostic. But this will all change in the Tribulation, when the Antichrist comes to power, then survives an assassination attempt, and enters the Jewish temple in Jerusalem insisting to be worshipped as God. People won’t be able to deny the power of the supernatural, and Satan’s deception will be in full force. They will worship the Antichrist, and the one who empowers him, as the God they didn’t believe in before.
The Tribulation period brings to a head the separation between those who have submitted to God and those who have rejected Him. It will force everyone to take a side: either worshipping God or being deceived into worshipping the Antichrist. Finally the tares and the wheat are separated, and marked for salvation or for destruction.
God has known all along what it would take: Jesus, the Lamb, “was slain from the creation of the world”. Even as God was creating the world, He knew that sin would enter it and thus necessitate the death of His Son. And He also knew all of those who would come to believe in Him, writing their names in the book of life.