Revelations was written during a time of great persecution on the church.
John MacArthur writes in his commentary on Revelation that the third century church leader Tertullian noted, “If the Tiber reaches the walls, if the Nile does not rise to the fields, if the sky doesn’t move or the earth does, if there is famine, if there is plague, the cry is at once, ‘Christians to the lion!'” In other words this was a time where if anything went wrong, blame was cast upon Christians along with grave punishment.
In Revelations God gives the Apostle John a vision that would, could and should encourage, and bless His churches throughout all generations.
With Christians living in constant fear of torment and death Jesus gives them follow-up revelation letting them know that He is still in control.
Death and Hell, I believe are easily the two most feared subjects in the Bible. No one wants to die and definately no one wants to go to Hell. Notice what the writer has to say about these two subjects:
Revelations 1:17-18 – “And when I saw him, I fell at his feet as dead. And he laid his right hand upon me, saying unto me, Fear not; I am the first and the last: 18 I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death.”
Jesus was the first to ever conquer death and can never die again. He not only conquered it but got the keys to death and Hell along the way.
In other words it is our High Priest, Lord, and King that will decide who dies the second death and spends eternity in the Lake of fire.
Men may threaten us with the death of our physical bodies but Jesus holds the only set of keys to eternal death and Hell!