Are Your Loved Ones in Hell?

In a recent TV program, Pat Robertson said that the wicked are suffering in hell fire, and that even Samuel was in the darkness of hell at the time of King Saul. But is this true? Where does the concept of an ever-burning hell come from? What does the Bible mean when it speaks of the lake of fire where the wicked would be cast into? And what is the outer darkness where there will be weeping and gnashing of teeth?