Judaism, Christianity and Islam all hold that god is perfectly good1. This omnibenevolence is one of the three "omnis" of a creator god, the others are omnipotency (all-powerful) and omniscience (all-knowing). Benevolence has long been a feature of theism; Euripides (fifth century BCE), said that "if the gods act in a shameful way, they are not gods"2. But, being 'perfectly good' contradicts other elements of God's nature. God could be neutral (amoral) or malevolent (evil and immoral) but it cannot be perfectly good.
Omnibenevolence Contradicts Free Will: It God is perfectly good then it always makes the most perfect choice - and therefore, has no choice: no free will. A being with no free will cannot be morally good as it makes no moral choices; it can only be morally neutral.
Omnibenevolence Contradicts God's Status as the Sole Creator: If God's actions and wishes are automatically good by definition, then, whatever it does, it is perfect. This makes its morality arbitrary. Conversely, if God's actions are not by definition good, then, there must be an independent source of the definition of goodness by which God's actions are compared - God can't be the creator of goodness - so what was?
Real-World Evidence: The real-world existence of evil and suffering is also evidence that the world was not created by a perfectly good god. Natural disasters such as earthquakes and volcanoes appear to be universal and not linked to Human free will, yet they cause much destruction, as do genetic diseases and other horrible afflicts that effect the innocent. If god had free will and was perfect, it would have created all living beings as both having free will and also in a state of perfection. It did not, and so God is not an omnibenevolent creator.
In more detail:
These verses are vastly outnumbered by those that show that God is not good; some like Isaiah 45:7 are unambiguous - "I form the light and create darkness, I bring prosperity and create disaster; I, the LORD do all these things". Regardless of the reason for such actions, god cannot be absolutely and perfectly good if it does those things. I have a long page that details some of the more obvious and infamous instances of the evil of the Biblical God; that page's menu is:
There are four philosophically strong arguments that God cannot have free will. Here they are:
An omniscient being cannot have free will because it is predestined by its own certain knowledge of its future actions. To change its mind would be to contradict its omniscience.
A perfectly benevolent God cannot have free will because there is only one perfect course of action, which God, being perfectly good, must follow. Even if it could choose its future actions, there is only ever one course - the most perfect one. To exercise free will to veer off this course contradicts God's perfection.
The creator of time cannot have free will: if God exists outside of time then it is immutable, unchanging, and as such it has no mental states except one everlasting and perfect state. Choices require changes in mental states over time. An eternal being that created time cannot already have free will.
If God created free will then it cannot itself already have had free will before it done so: yet, an omniscient being already knew (before it created free will) everything it would do. Therefore, any creator-god cannot have free will about any of its actions.
For more, see:
A lack of free will also means that God is amoral. What is the point of saying that God is moral, if God cannot choose to do anything imperfect? How can it be a moral being, if it has no moral choices? The answer is that God is a morally neutral (amoral) being.
If God is the ultimate creator of everything, then, God created good and evil. Given that 'good' and 'evil' are parts of creation, does it make sense to define the Creator as one or the other? Many theists simply say yes! but it causes inherent logical contradictions to define God as benevolent:
“One problem with this approach has been called the Euthyphro dilemma (from the discussion under that name in Plato's Dialogues). In brief, this puts forward two alternative positions that a religious person might take: either what God commands is right simply because God commands it, or God commands what is right because it is right. The first of these alternative, what might be called the fundamentalist position, seems to imply that God's command sets an arbitrary standard which we have no moral reason for following; we may indeed only follow it out of fear of the consequences of failing to do so. The second alternative is equally troubling for the religious person. It seems to imply that the divine command is irrelevant to ethics and that ethical standards are established independent of religious considerations. It also sets limits on divine omnipotence by suggesting that God is compelled to act in a certain way because that is what is ethical.”
In order for God to be Good then someone other than God must explain and define what goodness is. Otherwise the word "good" would be devoid. As God cannot be the basis for goodness, the statement "God is good" is meaningless, and statements like "God wills us to do what is good" is therefore not true as "good" in this context is empty. The result is that if God exists, it does not define morality or goodness - it must come from a different source. If it comes from a different source then God did not create it. An impossible situation for most theologians. The only escape is to cease to consider god to be good (it can still be a creator, just an amoral one).
Some theists say that God is the basis for ethics and moral goodness. Everything that contains God is Good, and vica-versa, because God is pure goodness. But reality is not that simple. The philosopher Bertrand Russell explains:
“Kant, as I say, invented a new moral argument for the existence of God, and that in varying forms was extremely popular during the nineteenth century.. It has all sorts of forms. One form is to say that there would be no right or wrong unless God existed. [...]
If you are quite sure there is a difference between right and wrong, you are then in the situation: is that difference due to God's fiat or is it not? If it is due to God's fiat, then for god Himself there is no difference between right and wrong, and it is no longer a significant statement to say that god is good. If you are going to say, as theologians do, that God is good, you must then say that right and wrong have some meaning which is independent of God's fiat, because God's fiat's are good and not bad independent of the mere fact that He made them. If you are going to say that, you will then have to say that it is not only through God that right and wrong came into being, but that they are in their essence logically anterior to God.”
Lawrence Krauss makes the same argument that the devine definition of right/wrong cannot be arbitrary, but that it must be based on some principles:
“If one argues, as many deeply religious individuals do, that without God there can be no ultimate right and wrong - namely that God determines for us what is right and wrong - one can then ask the questions: What if God decreed that rape and murder were morally acceptable? Would that make them so? While some might answer yes, I think most believers would say no, God would not make such a decree. But why not? Presumably because God would have some reason for not making such a decree. Again, presumably this is because reason suggests that rape and murder are not morally acceptable. But if God would have to appeal to reason, then why not eliminate the middleman entirely?”
From the point of view of the individual, many theists hold that without God, a person can perform no good acts: All good acts are attributed to God but all bad acts are due to our rejection of God. However this is an inconsistency and is devoid of meaning when we think about the nature of a "good act". God wills us to do good acts. This must mean one of these two things:
If God wills it, then it is good. This implies that there is no real absolute good or morality, there is merely divine bossiness. If there isn't a moral reason for something to be good, then, is it really good? This position manages to make god's will good, but, it destroys the meaning of good.
God wills it because it is good. If God chooses actions because they are good and god is itself good, then, what created and defines this goodness? If god defines goodness, we are in the position above where goodness is an arbitrary term. If God doesn't define goodness, then, is God really the creator of good after all?
It seems that both these positions destroy each other and can be deflated to "God wills us to do what God wills us to do", which is hardly the basis for a moral system. The atheist philosopher Robert Le Poidevin goes as far as to argue that the goodness of god is a requirement of theism, and that its impossibility simply means that god cannot exist.
“Theism in other words, is self contradictory and hence false. We can construct an exactly parallel argument substituting "God wills us to do what is good" with "God is Good" and by doing this we capture the challenge to theism posed by Plato's dilemma.”
Robin Le Poidevin "Arguing for Atheism" p75-76
The simple statement that "god is love" and that all love comes from God is far from just being a throwaway feel-good statement that theists use. Attributing mankind's most potent and pleasing emotion to a benevolent deity is a traditional and natural maternal instinct for those who believe in a white light god, as all their feelings of humility, power, grace and love are personified in their god. But it is an inhumane and hurtful statement which undermines the value of loving relationships.
To say "God is the source of love" is to deny human love, love between people. It makes love cheaper, more arbitrary and less personal and caring. Humans beings themselves are the source of love, and love between people is due to their own feelings, to take away their responsibility for this feeling and say that it depends on God is inhuman. To love someone purely with your heart and emotions is good, but to explain it away or want to take less responsibility for feeling and wanting that love is hurtful.
If you love a person, you love them for who they are, and not because God inspired it! Love comes from your own choice and will. To think that love comes from our chemistry, our bodies and emotions rather than someone or somewhere else is in itself loving and caring. It makes our bodies and chemistry special. To say that God Is Love is to deny love the good power it has in the real world. You want the person you care for to love you, and that love to be from them and not due to religion, theology, social pressure or false sources, you want it to come from their will, not from God's.
If God is all-powerful and all-good, it would have created a universe in the same way it created heaven: with free will for all, no suffering and no evil. But evil and suffering exist. Therefore God does not exist, is not all-powerful or is not benevolent (good)7. Such arguments have been used by many philosophers as evidence against belief in god8,9. A theodicy is an attempt to explain why a good god would have created evil and suffering. The most popular defence is that it is so Humans could have free will. However the entire universe and the natural world is filled with suffering, violence and destruction so any Humanity-centric explanation does not seem to work.
For more, see:
The page linked above examines all of the main attempts to reconcile the existence of a perfectly good creator god with the existence of much evil in the world.