Old Testament
Isaiah 22:22
And I will place on his shoulder the key of the house of David. He shall open, and none shall shut; and he shall shut, and none shall open.
New Testament
John 10:7
[Read also, Revelation 3:7, 11-12]
So Jesus again said to them, “Truly, truly, I say to you, I am the door of the sheep.”
Keys lock and unlock doors, suitcases, filing cabinets, and even diaries – things that protect us and our property from intruders who might harm us or take our valuables.
The prophet Isaiah compared the Messiah to a “key” that permanently opens and shuts, but Jesus also identified Himself as the “door”. So, which is it? Is He the door, or is He the key that opens the door?
I think Jesus gave us the answer. After Peter declared, “You are the Christ, the Son of the living God!” [Matthew 16:16], Jesus said to Peter, “I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven” [Matthew 16:19]. In other words, what you unlock (forgive) no one will be able to lock again; and what you lock (do not forgive) no one will be able to open!” In Matthew 16:19, Jesus gave authority to US! [see Galatians 6:1]
When you forgive someone, they are truly forgiven by the power of Jesus; but when a sinner does not repent and refuses to seek forgiveness from God, then you (in love) must tell that person he is not forgiven... there can be NO forgiveness without admitting sins and seeking forgiveness. It is wrong to forgive a Christian brother who doesn’t see his sin or his need for forgiveness. We do not show God’s love if we allow a brother to continue in his sin. Ongoing sin without seeking forgiveness leads to eternal damnation. Unless the brother wants forgiveness, he will face God’s wrath and judgement of damnation. Withholding forgiveness is very serious and should only be done when the eternal wellbeing of a fellow Christian is in danger because of unrepentance. Note: Jesus NEVER gave us authority to tell someone, “DAMN YOU!” out of anger.
Jesus is also the “door of the sheep”. Everyone who belongs to His sheep fold will be allowed to enter His Kingdom through HIM! To enter His Kingdom, we need full forgiveness that comes ONLY through the power of Christ’s blood. So, HOW do we receive His forgiveness? Only by FAITH that leads us to CONFESS our sins to God, believing that His death fully ransomed us from the curse of sin, which is eternal damnation.
SO, Jesus is the Door, and the Key that opens the Door. Heaven is open to those who confess their sins, but it is locked against those who do not confess. Isaiah warns that (for the unrepentant) the key will “shut [the door] and none shall open.” Brothers, rejoice and be glad... because of your faith the door has been opened to you! It will NOT be shut again!