A "reward" in the Bible represents something that brings people together, or brings spiritual states together, and binds them. In the Bible, of course -- especially the New Testament -- we're told repeatedly to do what is good and right "without thought of reward." That's because removing the idea of a natural reward lets us be aware of spiritual rewards, which are actually intrinsic to the good that's being done. On a relatively low level, we feel delight in doing something nice and useful for someone else; that delight is a reward. The love that can exist between partners in a committed, loving marriage is a reward. The delight we feel when we truly want what is good and know how to create it is a reward. And ultimately, our conjunction with the Lord and the delight of His love and salvation is the deepest reward of all. These are the things meant when the Bible speaks of "rewards.

42. The Lord is called King and the Anointed. That is because He was the Messiah or Christ, and Messiah or Christ means King and Anointed. The Lord is accordingly also meant by King in the Word. He is by the same token meant by David, who was king over Judah and Israel.

That the Lord is called King and the Anointed of Jehovah is apparent from many passages in the Word. We are told, therefore, in the book of Revelation:

...the Lamb will overcome them, for He is Lord of lords and King of kings. (Revelation 17:14)

And in another place:

(He who sat on the white horse had) on His garment...a name written: “King of kings and Lord of lords.” (Revelation 19:16)

It is because the Lord is called King that heaven and the church are called His kingdom, and that His advent into the world is called the Gospel of the Kingdom.

That heaven and the church are called His kingdom may be seen in Matthew 12:28, 16:28; Mark 1:14-15, 9:1, 15:43; Luke 1:33, 4:43, 8:1, 10, 9:2, 11, 60, 10:11, 16:16, 19:11, 21:31, 22:18, 23:51.

And in Daniel:

...God...will cause to rise a kingdom which shall never be destroyed...; it shall break in pieces and consume all (other) kingdoms, while it shall stand forever. (Daniel 2:44)

Again in Daniel:

I was watching in the night visions, and behold, One like the Son of Man, coming with the clouds of heaven! ...Then to Him was given dominion and glory and a kingdom, that all peoples, nations, and languages should worship Him. His dominion is an everlasting dominion..., and His kingdom the one which shall not be destroyed. (Daniel 7:13-14, cf. 7:27)

That His advent is called the Gospel of the Kingdom may be seen in Matthew 4:23, 9:35, 24:14.