Who Are the “144,000”?

144000_title“And I heard the number of those who were sealed, one hundred and forty-four thousand sealed from every tribe of the sons of Israel.” – Rev. 7:4

“Then I looked, and behold, the Lamb was standing on Mount Zion, and with Him one hundred and forty-four thousand, having His name and the name of His Father written on their foreheads … And they sang a new song before the throne and before the four living creatures and the elders; and no one could learn the song except the one hundred and forty-four thousand who had been purchased from the earth.” – Rev. 14:1,3

Who are these mysterious people so numbered in the book of Revelation? Since they are sealed in the events of the last days, what do they have to do with us? Additionally, why is it that, in this particular book of the Bible that is more beset with symbols, metaphors, and images than any other book, is this listing of the 12 tribes of Israel inconsistent with all other similar listings in scripture? Could it be a clue as to the identity of this group called “the servants of God” (Rev. 7:3)?