Well, God - as I see it - both loves and hates. The phrase "God is love" is to be taken ... well, metaphorically, in a way. I don't think 'metaphorically' is the right word to use here, but you see what I'm trying to say?
I'm assuming you're referring to the Christian God. I'm not a Nazi Christian, by the way ... I'm just a Christian, hoping to answer your question
... I was, for several years, an agnostic (leaning more towards atheist), so I'm not looking to get on anyones bad side.
Anyways, back to the original topic.
While God's nature is love, he is also righteous and holy. God doesn't owe anyone anything - humanity sins. We are all sinners, and as such, we have offended him, because we broke his rules. His rules are a reflection of what he is like.
If you don't understand, let me try to explain in this way: Imagine a father with four kids. Two of the kids are very rebellious - all they want to do is go against their dad's rules, and then when they turn eighteen, they pretty much abandon their father, and go tell all their friends that their dad walked out on them. Their friends only see what the kids say, so they see the father as a bad person. The father, however, isn't a bad person - he justly punishes the two kids for being rebellious brats
The other two kids, while they do get punished when they do bad things (because they are only kids, and are prone to doing bad things
) seem to magically have life easier with their father, though ... because they "believed" in their father's rules. They trusted them to be right, and did what he said - even though they may have had several conflicts with them in the past.
The dad doesn't owe his kids anything ... the kids actually owe their dad! But the dad isn't going to hold it against him, of course.
Back to talking about God. I also, personally believe that if God was to suddenly save the entire world and let them off the hook ... well, what would the purpose in that be? If you had a few kids that just went and got themselves laid and all kinds of other crazy things in a night (bad things, whatever your idea of bad is), when they came home, would you say, "Oh, it's okay, just don't do it again!" ... or would you punish them?
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Edit: What proof is there that God does not exist, besides "I haven't seen him yet"?