The Word of God tells us that one's existence does not end when a person 's body dies but continues on forever. It will either be in the presence of God or in a place of punishment. In the presence of God will be the ones that have accepted Jesus as their Savior and He is the Lord of their life. The place of punishment is relating to the lost.
Jesus taught that there is a place of eternal punishment for those condemned before God. Matthew 23:33; "Ye serpents, ye generation of vipers, how can ye escape the damnation of hell". Jesus is a righteous and loving Christ, so it seems strange that these words came from Him. Jesus was talking to ones that were furious, malicious adversaries to Christ and the gospel. He wanted them to know where they were going.
To make sure you don't go to a fiery hell there is one way to escape it and only one way. The way is to repent of your sins, ask Jesus to forgive your sins, ask Him to be your Lord and Savior and have faith Jesus will forgive your sins and be your Savior.
If you don't do this, your eternal life will be spent in a place of fire that never shall be quenched. There will be wailing and gnashing of teeth. Matthew 13:41-42; "The Son of Man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity; v. 42 And shall cast them into a furnace of fire: there shall be wailing and gnashing of teeth". In these two verses Jesus is telling what will happen to all who cause sin and do evil. There will be great suffering. This place was prepared for the devil and his angels.
This is what happens to a soul that rejects Jesus Christ as Lord God Almighty.