1. Christ, who has the keys of death and of Hades. (Rev 1:18)
    Deut 32:39, 1 Cor 15:54-57,

The Old Testament prophesied that God would destroy death forever and wipe away our tears. (Isa 25:8, Hos 13:4)

Isa 25:8 He will swallow up death in victory; and the Lord God will wipe away tears from off all faces; and the rebuke of his people shall he take away from off all the earth: for the Lord hath spoken it.

Hos 13:4 Yet I am the Lord thy God from the land of Egypt, and thou shalt know no god but me: for there is no saviour beside me.

God has all sovereignty. Our life and death are in God’s hands. (Deut 32:39)

Deut 32:39 See now that I, even I, am he, and there is no god with me: I kill, and I make alive; I wound, and I heal: neither is there any that can deliver out of my hand.

Jesus conquered death by dying on the cross and resurrecting. Now Jesus has the key over death and gives victory to us who believe in Jesus Christ. (1 Corinthians 15:54-57, Rev 1:18)

1 Corinthians 15:54 So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.
55 O death, where is thy sting? O grave, where is thy victory?
56 The sting of death is sin; and the strength of sin is the law.
57 But thanks be to God, which giveth us the victory through our Lord Jesus Christ.

Rev 1:18 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.