The concept of Hell as a place of tortured souls came to Christianity a few hundred years after the Gospels were written. The teaching of Christianity is based on God's love to mankind, and the a place like Hell was rather contradictory to love.
There are some references in the New Testament on a place called Gehenna (Greek), which are translated to English as Hell. For example, in Matthew 5:22 and Mark 9:45. However, Gehenna was a valley outside of Jerusalem walls where the Israelites sacrificed their children into fire. King Josiah stopped the horrible practice (2 Kings 23:10) and turned Gehenna into a big garbage landfill.
During Jesus' lifetime, and the four Gospel writers after him, Gehenna was the landfill of the city. Other than domestic wastes, the people of Jerusalem also dumped dead bodies of criminals and animals to there. They added brimstone and kept the place burning. When Jesus said to the Jewish religious leaders at that time, "Serpents, offspring of vipers, how are you going to flee from the judgment of Gehenna? (Mat 23:33)", the people understood the message as throwing the dead wicked ones to the landfill, and not torturing the living ones for eternity.
Hence, for the first hundred of years, the loving Christians believe that good people will be resurrected in spirit and go to Heaven, to live an everlasting life with Christ. While the wicked ones will not receive the blessing of everlasting life, and their souls would be faded away and be forgotten.
So, when did the idea of Hell came to Christianity? Some suggests the idea of Hell came after interactions with Moslem Arabs in the seventh century.
