The main source of authority for Christians is the Bible.
Christians find many reasons in the Bible to believe in life after death. They include:
Eternal life – Jesus promised that his followers would have eternal life.
I am the resurrection and the life. He who believes in me will live, even though he dies.John 11:25-26
Jesus’ life as an example – God sent Jesus to Earth in order that humans could overcome death and have eternal life.
God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.John 3:16
Resurrection of the body – when Jesus rose from the dead he rose with a body. Paul teaches in the Bible that people will have resurrection bodies like that of Jesus.
So will it be with the resurrection of the dead. The body that is sown is perishable, it is raised imperishable; it is sown in dishonour, it is raised in glory; it is sown in weakness, it is raised in power; it is sown a natural body, it is raised a spiritual body.1 Corinthians 15:42-44
Immortality of the soul – Jesus told the criminal crucified with him that he would go straight to paradise.
And he said, ‘Jesus, remember me when you come into your kingdom.’ And he said to him, ‘Truly, I say to you, today you will be with me in Paradise.’Luke 23:39-43
Christians interpret the teachings of the Bible on life after death to mean that humans will have a spiritual existence after death, rather than a physical one.
Belief in life after death may be influenced by the meaning and purpose that it gives to the lives of Christians.