In the Bible, the "key" is used as a symbol of God's sovereignty.
Throughout the Bible, the word "key" appears eight times. In today's passage, Revelation 1:18, Jesus said that Jesus has "the keys of Hades and of Death."
God predestined each person even before creation and presides over their life and death. This is symbolized by God having the key of death. Of God, it is written in the book of Samuel that, "The Lord brings death and makes alive; he brings down to the grave and raises up. The Lord sends poverty and wealth; he humbles and he exalts. He raises the poor from the dust and lifts the needy from the ash heap; he seats them with princes and has them inherit a throne of honor." (1 Samuel 2: 6-8) The Lord has the power to save, kill, make rich or make poor.
It is through Abraham that God reveals such powers. In Genesis 20: 17-18, when Abimelech king of Gerar, the land of the Philistines, took Sarah, Abraham's wife, God shut all the wombs of the house. God closed the doors of all the lives of Abimelech's family. Then how did the door of the family's door open? The Bible clearly shows that when Abraham prayed to God, God healed Abimelech and his wife and maidservants to produce. This reveals the power of prayer and the sovereignty of God. In Genesis 29:31, when Jacob's wife, Rachel, did not have a child, God opened Rachel’s womb to conceive her children.
From the examples of Abimelech and Rachel, we know that God has the power to grant and close the life of men. Like in the case of Abraham, God grants such authority to believers who fully believe in Him.
Excerpt from the sermon of Rev. Abraham Park