God's Eternal Purpose...it's in chapter 2

Very important Old Testament prophecies concerning the Messiah's kingdom can be found in various chapter "2’s," and their fulfillment is found in an important New Testament chapter "2".

The Kingdom in Prophecy

The "time" element for the coming of the kingdom of the Messiah is found in Daniel 2:44. It would come "in the days of those kings" — the kings of the Roman Empire (approx. 31 B.C. to A.D. 476).
The "location" element of the prophecy is found in Isaiah 2:3 — "For the law will go forth from Zion and the word of the LORD from Jerusalem."
The "how" of the coming of the kingdom is prophesied in Joel 2:28-32, where God says that He will "pour My Spirit on all mankind."

The Kingdom Accomplished

The fulfillment of all three of these prophecies is found in Acts 2 in the New Testament! The preaching was within the days of "those kings," the Roman Empire (approx. 30-33 A.D.). It was first done in Jerusalem (cf. Acts 2:5,14). And it was accompanied with the outpouring of the power of the Holy Spirit (Acts 2:2-4, 16-21). Peter quotes Joel 2, and says "this is what was spoken of through the prophet Joel!"

Remembering these prophesies, all found in chapter "twos" in the Old Testament, and their fulfillment in a chapter "two" in the New Testament, makes it easy to keep it in our mind and teach it to others.