Jesus gives his power promise to his disciples in Luke 24:45-49 — that he will send the Holy Spirit.
Luke 24:45-49 New King James Version (NKJV)
45 And He opened their understanding, that they might comprehend the Scriptures.
46 Then He said to them, “Thus it is written, and thus it was necessary for the Christ to suffer and to rise from the dead the third day, 47 and that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem. 48 And you are witnesses of these things. 49 Behold, I send the Promise of My Father upon you; but tarry in the city of Jerusalem until you are endued with power from on high.”
The church is the only institution established by Jesus Christ. Here we gather and worship God. He gave us the power to be good stewards of his church. We worship him because he is Lord.
When he was about to ascend into heaven after his resurrection, Jesus said, “It is to your advantage that I ago away.” His power promise was a promise to send the Holy Spirit, indwelling inside of us.
The written word of God also is his promise.
The great commission is another promise. Jesus said it is written and it needs to be preached. Remission of sins means the effect of the sin in your life is stopped. It no longer has any power to destroy you. It’s wiped clean. It’s gone. Only the blood of Jesus Christ can do that.
One such prophecy that was necessary to be fulfilled is in Jeremiah. God declares he will raise up a shepherd (the Messiah) a son of David and will execute judgement and righteousness on the earth.
Jeremiah 23:1-6 New King James Version (NKJV)
23 “Woe to the shepherds who destroy and scatter the sheep of My pasture!” says the Lord. 2 Therefore thus says the Lord God of Israel against the shepherds who feed My people: “You have scattered My flock, driven them away, and not attended to them. Behold, I will attend to you for the evil of your doings,” says the Lord. 3 “But I will gather the remnant of My flock out of all countries where I have driven them, and bring them back to their folds; and they shall be fruitful and increase. 4 I will set up shepherds over them who will feed them; and they shall fear no more, nor be dismayed, nor shall they be lacking,” says the Lord.
5 “Behold, the days are coming,” says the Lord,
“That I will raise to David a Branch of righteousness;
A King shall reign and prosper,
And execute judgment and righteousness in the earth.
6 In His days Judah will be saved,
And Israel will dwell safely;
Now this is His name by which He will be called:
THE LORD OUR RIGHTEOUSNESS.