John Locke was a very clever man who made an excellent and influential argument for religious toleration in the middle of the seventeenth century. This followed a over century of violence in Europe between the old and new denominations of Christianity and a much longer period of resentment and ill treatment of European Jews and Muslims. Locke said that you can't and shouldn't try to make people believe something they don't, because true faith is something an individual must come to by themselves; if they convert to the “right” religion under torture or because they were persecuted, then it doesn't count. What's more, it is sinful to torture or persecute one another so you'll have buggered things up for your own immortal soul in the process.
But despite all this, he didn't trust non-believers. If you didn't believe in God at all, he said, then there was no disincentive (i.e. the threat of eternal damnation) to stop you being naughty.
And this view persists among some people of faith; a different kind of faith is okay, but no faith at all is not. Religious ethics are privileged, in the law, in education and the media above non-religious ethical frameworks such as Humanism. And the really sad thing is when atheists buy into this, and conclude that there are no absolutes and everything is relative. So...
We know that morality exists without the Abrahamic God. We have had many great civilisations who, whilst believing in supernatural entities, did not have anything like the benevolent Father who wants everyone to behave themselves. You might negotiate with the gods, spirits, ancestors or whatever, make sacrifices and give thanks, but there was no one divine law to which everyone had to adhere. What there always has been is a set of social rules to which everyone has to adhere. It is only for certain periods in our history where they have been completely inextricable from religious doctrine.
Of course, not all cultures are equal, but there is no evil unique to societies without God. Nor do monotheistic cultures have the monopoly on freedom, compassion, social cohesion or anything else we might value. So where does goodness come from?
Nephew Alexander has a dreadful book he asked me to read to him, full of religious poems (there's nothing wrong with religious poems, but these were all dreadful). I had to read a poem where a child misbehaves in all sorts of ways. Among other offenses, the child thumps his sister. But in the end he stoped because his mother explains that this is not the way that
God wants the child to behave. The poem doesn't explain that misbehaviour harms other people, but merely God.
Now clearly, that's not where morality comes from. Christians don't refrain from assaulting one another simply because they're frightened of the wrath of God. A good Christian refrains from assaulting other people because other people are valuable; their feelings matter. Also, justice matters and violence is unjust. A Christian may add that God loves and feels for all people and justice is God's will, but that merely supports the decision they have already made not to thump a person. I hope.
I don't think you can describe a two year-old as a Christian, but Alexander is most certainly a moral person. His interactive play is very much concerned with working this stuff out. One of his earliest games involved giving and taking. It doesn't really matter what the object is, but he wants to give it to you and take it from you and give it back and so on. Sometimes he offers a thing, but doesn't give it. Sometimes he snatches a thing away. He is very interested in objects that are forbidden; he might attempt a swap or get upset if you won't hand over the thing he wants.
And he exhibits kindness and appreciation for others. He feeds his friend and teddies, he shares thing out. He gives hugs and kisses and says
Peas when he wants something – something we've interpreted as
please (although quite possibly, he just likes peas). Not yet two years old, Alexander already has a rudimentary grasp of that fundamental rule of all human morality, the Golden Rule,
do as you would be done by. *
A small child is in an extreme version of the position we all share; he is dependent on other people. If he was to mess up in a big way, and everyone walked away from him, he could not survive. So his interest in co-operation is as deep-rooted as his fear of loud noises and his pleasure in sweet food. He cannot afford to be neglected or abandoned.
This is not to suggest that we are all born good. Small children must manipulate those around them to meet their needs, whatever that takes. Alexander is learning by example, experience and experiment. He is very fortunate to be finding that kindness is met with kindness, but he has to keep testing. He pushes at the boundaries, he tests patience. He has to find out what's possible. Other children learn other strategies, some not nearly so nice.
We are excellent adaptive organisms in this respect; our instincts are at once selfish
and altruistic. There isn't always even a clear dichotomy between altruistic and selfish motives – nor should these be necessarily be associated with
good and
bad. Someone once pointed out that true altruism, in evolutionary terms, might be to go round pricking holes in condoms, thus facilitating other people to pass on their genes far more often than they would otherwise. But passing on one's genes is not the goal of the individual. It is merely side effect of other instincts we have (sexual desire and the love of children); it doesn't actually make people happy
just to be a biological parent.
Christian doctrine acknowledge this, although tends towards the view that all actions motivated by instinct are bad and sinful and good things can only come from spirituality (a rather scathing attack on the designer). In any case, both heathens and theists can at least agree that we are somewhat conflicted.
Morality is the answer to this conflict. I 'm not sure whether to steal your pretty stone; on the one hand I want it, on the other hand I don't want you to lose it. A moral code informs me that it is better not to steal so I refrain. And where does that moral code come from? Well, it's logical. The potential consequences of an action outweigh the potential gain.
Like maths, moral philosophy is partly instinctive; most of us would be naturally able to tell that a group of seven pebbles is greater than a group of six pebbles, but we get a lot further quicker when we are taught how to count and do arithmetic. At this point in history, we inherit a lot of knowledge about both maths and moral philosophy, but none of it is useful if we swallow it raw. We need to be able to understand and to argue for the the things we hold to be true.
If I assert that the square of the hypotenuse is equal to the sum of the squares of the other two lengths in a right-angled triangle (breath), I don't need to claim this is true because Pythagorus said so and Pythagorus was magic; I can show you that it is the case (
here, see). Similarly, if I assert that we should not murder one another, I don't need to justify this because it was written in the Bible and the Bible is magic. The validity of a moral argument lies in reason, not revelation.
And yet morality as arrived to by reason is by no means inconsistent with religious belief. The vast majority of moral philosophers in our history have had religious faith of some variety. God would be logical too, right? However, belief in God is neither a necessary nor sufficient condition for knowing the difference between right and wrong.

Congratulations to anyone who read this far on a weekday. Here is a picture of a duck as a reward.
*In her
The Bible: The Biography, Karen Armstrong writes about a Pharisaic sage called Hillel,
It was said that one day a pagan had approached Hillel and promised to convert to Judaism if he could summarize the entire Torah while he stood on one leg. Standing on one leg, Hillel replied: 'What is hateful to yourself, do not to your fellow man. That is the whole of the Torah and the remainder is commentary. [...]'