It's popular for many today to quote passages dealing with evil in the Bible, and use it against the Bible. It's done either in the tone of "Look! Evil! That must mean this book is evil!" or "This happened in the Bible, this must mean God approves it." How many times, for example, have we heard the story of Lot and his daughters (Gen 19:30-38) quoted as if to embarrass us that it exists in the Bible?
Let's review a few things regarding this:
Firstly, let's clarify what the Bible is. The Bible is not about how nice a guy Jesus was. It isn't about how God is nothing but love, love, love, exciting and new. It isn't about how wonderful a people Christians are. It isn't about how great the world would be if we were just all so gosh darn nice to one another for a change. It isn't about how better your life can be. It isn't about getting rich. It isn't a children's book. And it most certainly isn't about buying some panhandling kid a pair of goofy shoes.
What is the Bible about, then? It is the story of mankind's fall and his salvation by the merits and salvific atonement of Christ. In order to talk about mankind's salvation, however, one must give a reason for man to be saved, and that entails either a discussion of or examples of mankind's evil. How can you possibly understand the words of the apostle Paul, that all men have sinned and fallen short of the glory of God (Rom 3:23), unless you see this discussed or displayed beforehand?
Secondly, and on that same train of thought, it is fallacious to assume that the mere mention of evil makes an entire work evil. A work on the proper mode of government would have to, by example, give poor examples of leadership, as Machiavelli does in his famous work, The Prince or his other, lesser known work, The Discourses. Yet if an author gives poor examples of leadership so that we may more properly understand the better examples, that does not give us the right to simply dismiss his entire argument. If anything, it's a fine example of not seeing the forest for the trees.
Thirdly, it is fallacious to state that, simply because a writer includes evil in his work, he must somehow approve it. According to such logic, an author who writes on the Holocaust must approve of the Holocaust, irregardless of whether or not he wrote on the Holocaust as an evil and barbaric act of inhumanity. In like manner, simply because an incident is recorded in scripture does not mean God approved of it.
Is there evil in the Bible? Yes there is. There's incest, rape, fraud, the murder of best friends, the breaking of oaths, and other examples. Yet man is a fallen creature, and even unbelievers would agree that man is capable of doing all the aforementioned evil. The Bible does not mince words when it comes to mankind's depravity. Men in toto are by their nature objects of wrath because of their sin (cf. Eph 2:3). Let us therefore give thanks to God for Christ, who "knew no sin," yet became sin "so that in him we might become the righteousness of God" (2 Cor 5:21). The Bible does mention evil, but it likewise tells us how we are able to flee from it and seek the righteousness of God.