He tells Saul (if I remember correctly) to murder subjugated people, women and children included, so at that moment to any sane person God is actually acting as a force of evil, corrupting the believers, who wanted to save them (for a life of slavery most probably, but still, better than murder).
He makes a bet with the devil over Hiob's life, and kills his entire family (or allows it to be killed, same thing) just to see that Hiob's indeed faithful (which he knew beforehand because he's omniscient, but whatever).
God of Old Testament even calls itself "jealous", and tells people he "punishes sins of ancestors on X generations" (3 or 4 if I remember correctly).
Kinda angry and evil, isn't it?