Religious people do not have this problem at all. They understand that we are all individuals and God has given us the right to choose in any given circumstance, regardless of nature, nurture or situation and only God knows for sure what your choice will be.
The reason there is a difference is probably down to two things:
Religious people are usually more than happy to judge, blame and punish people for their actions as they 'know' it was done through choice.
Atheists want to believe they have free will but do not want to say anything that suggests a supernatural entity or explanation for the freedom from the laws of physics that they seek.
Actually, religious people should pick athiests up on this point in debates!
There are actually only 3 possible ways will in the universe works:
- We obey classical physics and so with enough information every aspect of our lives can be predicted accurately before we are even born until the point of death. Free will is a myth.
- We obey a mix of quantum and classical physics so even though we do not know exactly what will happen to us we know probabilistically what will happen to us and what we will do at every point in our lives. Free will is statistically predictable.
- We have an ability that transcends the laws of physics and so, by definition, free will is supernatural.
One of these three must be the case. A good atheist has to select 1 or 2 but the religious happily choose number 3.
The problem for most atheists, other than their wish to have free will, is what the impact of no free will means for society. How do you blame someone for committing a crime if you realise they had no choice. How can you justify punishing them? It plays along the lines of: without god all things are permitted.
This is absolute nonsense. When you have a puppy and it makes a mess on the carpet, it had no choice, no view on the moral rightness of its actions, yet you punish it anyway to stop it doing it again. The same s true of humans. Punishment and rewards are how we are pushed into acting.
Once we (society) decide an act is undesirable we make a punishment for it. Punishing an act has three fundamental parts:
- Punishment as justice
- Punishment as deterrent
- Punishment as a solution
The punishment as justice argument is redundant as we have no free will.
However by making an act punishable we make it less likely to happen, the pleasure of the act (in some people or some situations) being outweighed by the fear/likelihood of punishment.
When it does happen we stop the perpetrator from being able to recommit the act by locking them up or removing certain rights from the person, e.g. a person who is cruel to animals can no longer keep animals.
It does not mean that we remove mitigating circumstances though, or diminished responsibility. Those are still valid once free will is removed.
From this we can see that the justice system will tick along nicely after we have removed the concept of free will.