Ray Bradbury wrote a little book called Something Wicked This Way Comes.T. H. White wrote a slightly larger book called The Once and Future King.
While involving themselves in totally different plots, histories, and worlds, they actually blend together quite well (well, parts of them, anyways).
A major point that Bradbury makes is that being righteous and good does not necessarily lead to happiness. On the contrary: it is those who do the most evil that receive the most satisfaction from this world. They siphon away joy and life from everything. The good shine out, trying to give love, life, and joy to the universe around themselves—even at the expense of themselves. Evil will not make that sacrifice; there is no satisfaction.
Because of this, the life of a good man is often sad and painful.
White’s King Arthur brings up a very valid point: satisfaction is not happiness. As he puts it (more or less, I’m paraphrasing), evil men are never happy or joyous. Victorious? Yes. Happy? No.
King Arthur makes this observation as Camelot crumbles around him; he’s reminiscing, seeing if there are any regrets.
Letting the echoes of these two excellent authors resonate within ourselves, one conclusion becomes evident according to them: evil is not a path to happiness. It can substitute, but never truly quench the thirst for happiness.
Is good and righteousness a path to ultimate happiness? I don’t know.
I do know that, while King Arthur has never met a truly evil man that attained happiness, I have seen (and I believe met) a few good people that have.