The Bible describes Hell as "the fire that shall never be quenched." Sinners better hope that these fires are literal, because, if figurative, eternal damnation is something worse than a "furnace of fire", since a symbol is less, not greater, than the thing symbolized.
Hell is a testimony to the power, wisdom, and love of God, who created Hell not for man but for the devil and the fallen angels. Later man followed Lucifer in rebellion and consequently God has at intervals enlarged Hell to accommodate the multitudes of unbelievers that fall into "the bottomless pit" daily.
What else in the end is God to do with the wicked? Since men are created with an immortal soul, even the Creator can't simply destroy that which is immortal. When men persistently reject God's mercy, judgment must finally be executed, or God is not loving.
Should God allow Heaven to become Hell by allowing the wicked to enter? The peace of heaven must not be disturbed. What makes heaven heaven, but the absence of evil?
The effects of sin are perpetual. In like matter the manifestations of the Righteous Judge's disapproval of sin must be endless. How many multitudes has an atheist like Bertrand Russell continued to influence long after his death through his writings? The torment of unbelievers in Hell will be an everlasting testimony of God's holy hatred of sin, and an eternal reminder to the glorified church that sin will condemned.
As miserable as sinners will be in Hell, they would be even more miserable in Heaven. They have hated the church militant so would they despise the church triumphant. They have preferred the companionship of fools over that of the righteous on earth, so they will in eternity.
It is a law of nature that the organism and environment must be in harmony. The surroundings of the incorrigible soul in Hell will reflect and express the sinners corrupt inward state.
Many are under the delusion that they will make peace with God before death. But the longer the sinner puts off the salvation of his soul, the less likely it becomes that he will ever change. Persistency in sin tends to a perpetual fixity in moral nature. Sin stupefies the ethical sense and one becomes insensible to the appeals of the Holy Spirit. The sinner may lose his recuperative power before he draws his final breath and is cast into "the lake of fire" from where there will be no recovery. Reader, this may be your final day of visitation.