Although God will bountifully extend the opportunity for salvation to all those who have never known Him, some will still refuse to repent, submit to God and receive His gift of eternal life.
What is their fate? The Bible reveals that, rather than suffering forever in an ever-burning hell as commonly thought, they will simply cease to exist.
Revelation 20:15 Revelation 20:15And whoever was not found written in the book of life was cast into the lake of fire.
American King James Version×tells us that, after the final judgment depicted by the Eighth Day, "anyone not found written in the Book of Life was cast into the lake of fire."
Revelation 21:8 Revelation 21:8But the fearful, and unbelieving, and the abominable, and murderers, and fornicators, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burns with fire and brimstone: which is the second death.
American King James Version×adds, "But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolators, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death."
Notice that their fate is clearly death, not eternal life in continual punishment.
Paul, too, understood that death is the punishment of the wicked. "For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord" (Romans 6:23 Romans 6:23For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
American King James Version×).
He contrasts death, which is what we earn because of our sins, with life, which is God's free gift to us because of the sacrifice of Jesus Christ in our place.
The prophet Malachi made clear the fate of the incorrigibly wicked: "'For behold, the day is coming, burning like an oven, and all the proud, yes, all who do wickedly will be stubble. And the day which is coming shall burn them up,' says the Lord of hosts, 'that will leave them neither root nor branch.
"'But to you who fear My name the Sun of Righteousness shall arise with healing in His wings; and you shall go out and grow fat like stall-fed calves. You shall trample the wicked, for they shall be ashes under the soles of your feet on the day that I do this,' says the Lord of hosts" (Malachi 4:1-3 Malachi 4:1-3  For, behold, the day comes, that shall burn as an oven; and all the proud, yes, and all that do wickedly, shall be stubble: and the day that comes shall burn them up, said the LORD of hosts, that it shall leave them neither root nor branch.
 But to you that fear my name shall the Sun of righteousness arise with healing in his wings; and you shall go forth, and grow up as calves of the stall.
 And you shall tread down the wicked; for they shall be ashes under the soles of your feet in the day that I shall do this, said the LORD of hosts.
American King James Version×).
To learn more about hellfire and the fate of those who ultimately refuse to follow God, read the Bible study aid Heaven and Hell: What Does the Bible Really Teach?