"For just as the Father has life in Himself, even so He gave to the Son also to have life in Himself;John 5:26(NASB)
Because God is eternal, He has life in and of Himself. God is the source of all life, the author of all life, the fount of life, and no other creature that has been made has life in itself. No other created being has this life, yet God gave the Life that was unique to Himself to the Son so that His only begotten Son has that same life in Himself.
But Christ Himself also has life in and of Himself, for He is the Word that spoke all creation into being. He also is the author of life, the well-spring of life, the fountain-head of life, and He is one with the Father in character and attributes, in holiness and power, in truth and in essence, in majesty and great glory.
But the Son alone became Man and took upon Himself the sins of the whole world. Jesus Christ uniquely gave His life as the ransom price for the sins of humanity. It is true that the Father loved the world so much that He gave his only begotten Son so that all who believe on His name would not perish but have eternal life – but only the Son spilled His human blood on Calvary to redeem mankind with His life-giving power.
Eternal life is received in no other way except through believing on Christ. "He that has the Son has life, but He that has not the Son of God does not have life – because he has not believed in the only begotten Son of God," as Saviour and Kinsman-Redeemer. "Salvation is found in no one else, for there is no other name under heaven given to mankind by which we must be saved."
As Son of God, Jesus is fully able to save all who believe on His name. But as Son of Man, the Father has given Him the authority to judge all humanity. And John was given a glimpse into the awesome throne room of heaven, where he saw Jesus perfectly embodying both these roles; the Lamb of God, slain to give humanity eternal life, and the Lion of the tribe of Judah, triumphant and able to judge the world.
God has put all things into Christ's hands until Christ is all in all including the gift of eternal life, the authority to judge, and the keys of death and hell.
Loving Father, thank you that Jesus Christ became a Man to pay the price for my sins, and that through Him I have been given the gift of eternal life, Your life in me. Thank You, in Jesus' name, AMEN.