Matthew 16:19
[And] I will give you the keys of the kingdom of heaven [i.e., for opening up the way into it]. And whatever [truth] you [and the other apostles. See 18:18] require [people to believe and practice] here on earth will have already been required of them [by God] in heaven. And whatever [truth] you do not require [of people] on earth, will not be required [by God] in heaven."
Matthew 18:18
Truly I tell you, whatever [truth] you disciples require [of people to believe and obey] on earth will have [already] been required [by God] in heaven. And whatever [truth] you do not require [of people to believe and obey] on earth, will not have [already] been required [by God] in heaven.
John 20:23
Whosever sins you forgive, they will be forgiven [by God]. And whosever sins you do not forgive, they will not be forgiven [by God]." [Note: Actual forgiveness would result only when people responded, by faith, to the Gospel message. See Acts 2:37-38].
Revelation 3:7
"And write [this] to the angel of the church at Philadelphia: These are the words of Him who is holy and true, [and] who possesses the key [i.e., the power and authority] of King David, [and] who opens [a door] which no one will close, and who closes one that no one will open:
Revelation 1:18
and the Living One. I was dead, and see, I am [now] alive forever and ever! And I possess the keys of death and of the unseen place of departed spirits.
Acts 2:14-42
But Peter [responded by] standing up with the eleven [other] apostles and, lifting up his voice, began to speak. He said, "People of Judea and all who live in Jerusalem, listen to what I am saying so you will understand this situation.
Acts 10:34-43
Then Peter began to speak. He said, "I perceive that God truly does not show favoritism toward anyone,
Acts 15:7
And after many questions were asked [about it] Peter stood up and addressed the assembly [including the former Pharisees who were now brothers]: "Brothers, you are aware that some time ago God decided that, from among your number, it would be through my ministry that the Gentiles would hear and believe the Gospel message.
1 Corinthians 5:4-5
[I command you], when you people are assembled together, with my spirit [also present], in the name [i.e., by the authority] and power of our Lord Jesus,
2 Corinthians 2:10
Now whomever you forgive [for doing] anything [wrong], I will forgive also. For indeed, whatever I have forgiven, if I have [actually] forgiven anything, has been for your sakes in the sight of Christ. [Note: Paul seems to be saying "Since my forgiveness depends on your forgiveness of the man, I am not sure of my forgiveness because I am not sure of yours"].
1 Thessalonians 4:8
So, the person who rejects [this exhortation] is not [merely] rejecting what man says but God [Himself], who gives His Holy Spirit to you.
Revelation 9:1
[When] the fifth angel sounded its trumpet, I saw a star that had fallen from the sky to the earth. And the key to the shaft leading to the deep pit [Note: This is thought to be the place where the devil and his demons live] was given to him.
Revelation 11:6
These witnesses have the authority to shut the sky up so that it does not rain during the time they are prophesying. And they have the authority to turn the waters into blood, and to strike the earth with every kind of plague whenever they want to.
Revelation 20:1-3
Then I saw an angel coming down from heaven, holding the key to the pit and a huge chain in his hand.