There are two appointments in life no one will ever miss. They are death and judgment. The Bible tells us in Hebrews 9:27 that it is appointed for men to die once and after this comes judgment. We cannot see the judgment to come. It is in the future. But we can see death everywhere. Since death is a reality facing all humans, why will judgment be otherwise? The Bible mentions them both together. Death, Romans 3:23 explains, is the wages of sin; Judgment is also necessitated by sin in this world.
We live in a world where often the wicked will prosper and go unpunished while the innocent and weak suffer. If this life is all there is, moral justice will not be upheld in this universe. But the Bible teaches us there is life beyond death. The Lord Jesus hence tells us in Matthew 10:28 not to fear men who can kill only our body but not our soul, but to fear God who can destroy both in hell.
Hell is such a place of terror, that the Lord admonishes us in Matthew 5:29-30 to cut off our hand or eye if it causes us to sin, because it is better to lose our body parts than to go into hell. Hell is a fiery furnace (Matt. 13:42) with unquenchable fire and worms that do not die (Mark 9:48). There will be weeping and gnashing of teeth (Matt. 13:42). It is a place of eternal punishment prepared for the devil and his angels (Matt. 25:41).
Most people in the streets have no sense of the torment hell will inflict. None has experienced anything like it in this world. People cannot apprehend the greatness of the punishment that is forever without change, without end, and with no escape, no help, and no comfort. They have little idea of how such despair stretching over eternity will befall them at death.
In the Gospels, Christ frequently warns his audience of hell because they are not fine, but in imminent danger that they are not sensible of. Are we not also obligated to tell the lost of their fate? Will we not be loving enough to warn our friends if they are asleep in a house on fire? Should we not always be praying like Paul in Ephesians 6:19-20, for open doors to boldly and sensibly proclaim the good news of salvation in Christ wherever God places us?