According to different Bible commentaries, in ancient Eastern countries, keys were sometimes carried over the shoulder as a symbol of power and authority.

This is fulfilled in Jesus' eternal reign, because the Old Testament Scriptures predicted that one day all government and authority would be under the Messiah's dominion. In other words, "the government shall be upon his shoulder."

"For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counselor, The mighty God, The everlasting Father, The Prince of Peace" (Isa. 9:6).

Therefore, talking about Jesus' eternal reign, the key of the house of David symbolizes Jesus' authority and power to "sustain the government on his shoulders."*

"Then cometh the end, when he shall have delivered up the kingdom to God, even the Father; when he shall have put down all rule and all authority and power" (1 Cor. 15:24).

Revelation 3:7 says that Jesus was given the key of David, indicating that all authority was given to Him. That's what the Bible means when it says, "...the government shall be upon his shoulder..."

As the Christ and Lord, Jesus literally brought to pass Old Testament prophecy to rule and reign forever and ever, which fulfilled the Davidic Covenant. Jesus was given the key of David to spiritually sit on David's throne and rule and reign over His people Israel - and of His kingdom there shall be no end.

Now you can see why Jesus is the One who has the authority and ability to open and shut doors.

"...These things saith he that is holy, he that is true, he that hath the key of David, he that openeth, and no man shutteth; and shutteth, and no man openeth" (Rev. 3:7).

Authority No One Else Possesses
What Jesus opens, no man can shut. Jesus also has the authority to shut doors, and what He shuts no man can open. The key of David means that Jesus has authority no man possesses.

Isaiah also prophesied about Jesus' authority to open and close doors. Notice that Isaiah also uses the phrase "the key of David" in connection with Jesus' authority. It is interesting that Isaiah also prophesied that God would "lay the key of David on Jesus' shoulder," talking about Jesus' reign.

"And the key of the house of David will I lay upon His shoulder; so He shall open, and none shall shut; and he shall shut, and none shall open" (Isa. 22:22).

The key of the house of David can also be understood as the power and authority to give access to God and to eternal life. We know that Jesus is the Authorized One giving us access to God and to eternal life because the Scripture says, "For there is one God, and one mediator between God and men, the man Christ Jesus" (1 Tim. 2:5).

Also, Jesus Himself said, "I have the keys of hell and death." No man has authority over hell and death.

"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" (Rev. 1:18).

He Took The Keys From Satan
Thank God, Jesus went down to the dark regions of the domain of death and led captivity captive (Eph. 4:8-9). He took the keys of hell and death away from Satan and arose on that glad Resurrection morning long ago - the Victor over death, hell, and the grave!

When Jesus arose from the dead, He went to tell His disciples. He gave them the revelation that He is the Authorized One because all power in Heaven and earth was given unto Him. The government is upon His shoulders! He alone has the key of David.

And as they went to tell his disciples, behold, Jesus met them, saying, All hail. And they came and held him by the feet, and worshipped him. Then said Jesus unto them, Be not afraid: go tell my brethren that they go into Galilee, and there shall they see me....

Then the eleven disciples went away into Galilee, into a mountain where Jesus had appointed them. And when they saw him, they worshipped him: but some doubted. And Jesus came and spake unto them, saying, all power is given unto me in heaven and in earth."
(Matt. 28:9-10,16-18)

Jesus told His disciples that all power had been given unto Him in Heaven and in earth. How could all power be given to Jesus? Because He is the Holy One; He is the True One; He is the Faithful and the True Witness.

He is the Authorized One - possessing the key of David - the key of power and authority forever. He is authorized to open and close doors. And Jesus has the keys of death and hell (Rev. 1:18).

Jesus is the only One worthy to open the book sealed with seven seals. He is the Holy One, the True One, and the Faithful and True Witness. He is the Authorized One; He holds the key of David and the keys of death and hell.

Source: Jesus, The Open Door by Kenneth E. Hagin
Excerpt permission granted by Harrison House Publishers