Two claims often made by the religious are:
The first of these can easily be shown to be untrue, as I shall demonstrate. The second, though usually intended as a warning, is really a cause for celebration, because morality in practice never was, and never could be, anything other than relative. Religion's attempts to enforce absolutism have usually led to unnecessary suffering.
Khalid and Noora, walking home from school, come across a small huddle of cockroaches. Khalid wants to stamp them out but Noora stops him: How would you like it if a giant came and stamped on our classroom?
That is morality in a nutshell, a degree of empathy coupled with an intuitive awareness of the Golden Rule - treat others as you would have them treat you. Jesus of Nazareth reputedly included this rule in the Sermon on the Mount (Matthew 7.12) but it is inconceivable that normal caring people had not already been living that way for centuries before.
The Golden Rule can be stated in two forms, positive and negative:
The second is less interventionist and therefore easier to follow. In fact, it almost reduces to: Don't be a prat! In other words, consider your actions and try not to hurt others.
The first suggests (or can be interpreted to suggest) that we should actively seek opportunities to treat others as they wish to be treated. But this should be handled with care. Sometimes people want to be left alone. Sometimes what they wish may not be in their best interests. Sometimes we may wholly misinterpret the situation. This is where the Golden Rule must be tempered with empathy. In many cases, the negative formulation is the safer option.
Khalid and Noora of course, as Muslim children, have never heard of the Sermon on the Mount, so where did their natural morality come from? Maybe Jehovah had a quiet word in their ears when Allah wasn't looking? Or, just maybe, responses we would call moral are a natural instinct in the human race. No God required.
We often hear it said that God sets an absolute standard of good and evil against which all acts are measured and without which any moral code is meaningless. But this is a non-sequitur. The absence of an absolute standard does not preclude meaningful differentiation between points on a continuum.
For example, we now have an absolute standard of temperature. We now know exactly how hot or cold the day is and can record it as a number of degrees. But for thousands of years before any such measurement was possible, people had no difficulty with the concept of hotter or colder. They didn't need a numerical readout to tell them not to wear furs in the desert sun or go naked in the snow. They knew the difference between hot and cold without knowing or caring about the absolute limits of either.
The same is true in the moral domain. We know that it is good to provide children with a secure environment and decent nutrition. We know it is better still also to provide education and encouragement. We know it is bad to neglect children's security and well-being. But it is worse still to actively abuse them. In other words, we have no difficulty understanding a continuum from very bad to very good. All of this is easily derived from the Golden Rule tempered with empathy and needs no supernatural input.
However no-one knows the absolute best way to treat children and most of us don't want to contemplate the absolute worst. Absolute standards do not exist, except in deterministic branches of the physical sciences. Beethoven's Fifth Symphony is a greater work than Pop Goes the Weasel, yet neither represents the end of the line from bad to good. That's not because the line doesn't exist; it's simply because it has no ends.
If we all based our morality on the negative formulation of the Golden Rule the World would be a far better place than it is. If we all correctly applied the positive formulation it would be a better place still. So why don't we?
Part of the problem lies with religious people who believe they have special knowledge of their God's standards of good and evil (especially the latter). This would be fine if they applied their privileged insight to their own behaviour only, but all too often they decide it is their duty to stamp out sin, like Khalid with the cockroaches. Better they should listen to Noora's restraining voice: How would you like it if someone treated you like that?
Morality is quite easy really - Don't be a prat. That's it.