The Lord Jesus in this description of himself states the wonder of his person, in that he is both God and man. We see his deity in the claim that he is the first and the last - it is a divine title used in the Old Testament of God (Isa. 44:6; 48:12). And we see his humanity in his claim that he died and came back to life.
As far as his deity is concerned, Jesus says that he is the originator of all things – the Creator, and he is the one who will wind up the current creation. So he is saying that he is the Controller of all things. In his human nature, he defeated death, the most powerful enemy of the human race. Even death cannot remove him from the place of supreme authority. Although he died, he reigns.
So the Smyrnians are reminded that Jesus is a great person who possesses two incredible abilities. He is the source of natural life and he is the source of resurrection life. The inhabitants of Smyrna were recognised for their devotion to the Roman emperor and he had given them rewards within his authority and power. In a far higher way, the Christians in Smyrna are urged to show their devotion to a far superior Ruler who could give them far greater benefits, even eternal ones.