[EDIT]: Short-form, less-ranty version: Many philosophers take omni-benevolence of god to be a required attribute. This is not apparent from the source material - so where does the idea stem from, if not the original source material? (Or, to use virmaior's phrasing, "Why does the philosophical account of God make omnibenevolence an attribute of God?")
[Looks to be shockingly similar to an earlier question]
So a while ago I was going through some of the thought experiments at philosophyexperiments.com. One of those experiments, titled Talking with God, goes through the standard Euthyphro Dilemma in a fun and amusing way.
Being an atheist, I answered honestly when asked if I believed a god existed or not. The quiz was amusingly offended by my lack of belief, and gave the following instruction for how to continue:
Okay, what this means is that you should assume all the questions that follow have this form: 'Is your archetypal God...', etc. In other words, you should figure out what sorts of characteristics you think are possessed by an archetypal "God", and then you should answer the questions that follow in terms of that concept of God. One thing you should bear in mind here is that you want your archetypal God to be logically possible, so you need to select a combination of attributes that are logically compatible with each other. Right, let's get on, I have other important stuff to do, prayers to ignore, that sort of thing.
The site then poses five questions before moving on: Is/Does God [sovereign/omnipotent/possess freedom of will/Intervene in the world/Omnibenevolent]?
To the last one - omnibenevolence - I said 'No' to without needing to deliberate on the question for very long at all. The archetypical god is capricious and cares little for human well-being (SEE: Every mythology ever created), and the deity described in the bible is no exception. The god of the old testament slaughters, tortures and encourages slavery. The 'redemption' in the second act when Jesus is introduced is clearly framed with 'Do not think that I have come to abolish the law or the prophets. I have come not to abolish but to fulfill' and 'Do not expect me to bring peace but a sword'.
So, naturally, the 'god' giving the quiz takes issue with my choice:
Also, what's this business of thinking I'm not omnibenevolent? Admitedly there was that whole incident where I slaughtered those Israelites because they peered into my ark. But come on, they had it coming. Also I think I should mention that as great a philosopher as Leibniz once noted that "it is generally agreed that whatever God wills is good and just".(Emphasis added)
So this rattled around in the back of my head, and it's been bugging me for a while now. What I'm wondering is: How did the Abrahamic concept of YHWH evolve from omnicidal maniac to an omnibenevolent deity? How did this god evolve from fear-and-obey-me to the source of all that is good and just?