The Real Story on King David:

1Samuel 8:6 But the thing displeased Samuel, when they said, Give us a
king to judge us. And Samuel prayed unto the LORD.7 And the LORD said
unto Samuel, Hearken unto the voice of the people in all that they say
unto thee: for they have not rejected thee, but they have rejected me,
that I should not reign over them.

the manner of the king that shall reign over you: He will take your
sons, and appoint them for himself, for his chariots, and to be his
horsemen; and some shall run before his chariots....14 And he will
take your fields, and your vineyards, and your oliveyards, even the
best of them, and give them to his servants.15 And he will take the
tenth of your seed, and of your vineyards, and give to his officers,
and to his servants.
16 And he will take your menservants, and your maidservants, and your
goodliest young men, and your asses, and put them to his work.17 He
will take the tenth of your sheep: and ye shall be his servants.

18 And ye shall cry out in that day because of your king which ye
shall have chosen you; and the LORD will not hear you in that day. 19
Nevertheless the people refused to obey the voice of Samuel; and they
said, Nay; but we will have a king over us;

Christ:
Jeremiah 33:15 In those days, and at that time, will I cause the
Branch of righteousness to grow up unto David; and he shall execute
judgment and righteousness in the land.16 In those days shall Judah be
saved, and Jerusalem shall dwell safely: and this is the name
wherewith she shall be called, The LORD our righteousness. 17 For thus
saith the LORD; David shall never want a man to sit upon the throne of
the house of Israel;

18 Neither shall the priests the Levites want a man before me to offer
burnt offerings, and to kindle meat offerings, and to do sacrifice
continually.

20 Thus saith the LORD; If ye can break my covenant of the day, and my
covenant of the night, and that there should not be day and night in
their season;21 Then may also my covenant be broken with David my
servant, that he should not have a son to reign upon his throne; and
with the Levites the priests, my ministers.

25 Thus saith the LORD; If my covenant be not with day and night, and
if I have not appointed the ordinances of heaven and earth; 26 Then
will I cast away the seed of Jacob and David my servant, so that I
will not take any of his seed to be rulers over the seed of Abraham,
Isaac, and Jacob: for I will cause their captivity to return, and have
mercy on them.