The God of the Bible is cruel and ill-tempered. Proof: According to many passages in the Bible, and accounts from many Christians, if a person does only good deeds but does not believe in Christ, he or she will be damned to an eternity of torment in Hell. See: http://en.wikipedia.org/wiki/Sola_fide
God, being omnipotent, could conceivably cause a non-believing soul to simply cease to exist. Instead, he chooses to sentence to Hell, or allow be sent to Hell (depending on interpretation), otherwise good people whose only sin was skepticism. Imposing, or allowing, a being to suffer an eternity of torment for the sin of mere skepticism is cruel and ill-tempered.
From Dictionary.com, a devil refers to an "atrociously wicked, cruel or ill-tempered person." The God of the Bible is a devil. Those who worship the God of the Bible are devil worshipers. I would rather suffer an eternity in Hell than worship a devil.