Proverbs 13:7  There is that maketh himself rich, yet hath nothing: there is that maketh himself poor, yet hath great riches. In this passage, we see two types of persons: the rich poor and the poor rich. Neither of the two is seemingly condemned, but the results are clear.

That one who has as a goal for his life, riches, (maketh himself rich) is in the end very poor. That one who has a goal for his life of poverty (maketh himself poor) is, in the end, a rich man. It seems like the first man is a continual sponge or taker; it seems that the second man is a like a river, always giving. The giver is, in the end, the rich man. The taker, in the end, is the poor man. This verse is like an oxymoron—a figure of speech in which apparently contradictory terms appear in conjunction (e.g., faith unfaithful kept him falsely true).

As always, we must make a spiritual beeline for Christ as our supreme example. Consider his work on earth from these verses in Philippians.

2:5  Let this mind be in you, which was also in Christ Jesus: 6  Who, being in the form of God, thought it not robbery to be equal with God: 7  But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: 8  And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross. 9  Wherefore God also hath highly exalted him, and given him a name which is above every name:

The servant or slave was not a rich man; he was a poor man. Christ became a servant on earth. (maketh himself poor)

2 Corinthians 8:9  For ye know the grace of our Lord Jesus Christ, that, though he was rich, yet for your sakes he became poor, that ye through his poverty might be rich.

The rich in this verse are described in this verse.  James 2:5  Hearken, my beloved brethren, Hath not God chosen the poor of this world rich in faith, and heirs of the kingdom which he hath promised to them that love him? The riches of faith are to be desired more than the riches of this world, temporal silver and gold or money.

Proverbs 10:22  The blessing of the LORD, it maketh rich, and he addeth no sorrow with it.

Luke 12:21  So is he that layeth up treasure for himself, and is not rich toward God.

2 Corinthians 6:10  As sorrowful, yet alway rejoicing; as poor, yet making many rich; as having nothing, and yet possessing all things.

Yes, the rich are poor and the poor are rich.

There is that maketh himself rich, yet hath nothing: there is that maketh himself poor, yet hath great riches. (Proverbs 13:7)