At the beginning of the Old Testament there exists a very interesting little story. This story has it that Adam and Eve, by eating from the "Tree of Knowledge of Good and Evil", were driven from paradise and closeness to God and made mortal and by implication this applies to all the rest of us as well.
This is a very insightful and profound story because it recognizes that knowledge of good and evil appears to be a cause of human suffering. They seem to have recognized a very important thing that we are also aware of today, namely this: One person's traitor is another person's hero. One person's terrorist is another person's messiah. One person's poison is another person's medicine. Thus we have direct contradictions of judgement embodied in the same person or object. These contradictions indicate that people's ability to judge good and evil is subject to the relative reality paradigms, (i.e. belief systems), which they construct, and thus people are not qualified for absolute knowledge of good and evil.
This is not to suggest that all relative reality paradigms are somehow equally valid. Some are definitely better than others--and one can tell this by looking at the results from their use. It is a mistake to assume that since human knowledge of good and evil is relative that truth is relative. It is not and anyone who tries to assert truth is relative is just trying to cover up their crimes.
So, when these relative reality paradigms meet, people must either compromise or agree on one or extend their knowledge and construct a new paradigm that they can agree upon or they soon will be fighting. Failure to agree has led to war after war. The writers of this thoughtful story about the tree appear to have recognized this.
Here's the kicker: Monotheism's holy books then go on to try to define absolute good and evil, thus establishing all kinds of things to "know" (absolutely) about good and evil, and thus negating the message at the very beginning. So first we have recognition that knowledge of good and evil is a basic problem, and second, the subsequent writings, in an attempt to solve this problem, define a morality that everyone must obey. Thus hopefully, they thought, ending the dissension over just what is good and evil, but also, unfortunately, ignoring the glaring contradiction this produced.
Their claim that this knowledge was handed down by God, through the human writers of the holy books and therefore that it must be followed and believed, ignores unfortunately, the actual workings of imparting knowledge of good and evil. While it is true that only a divine being can impart all of it, and it is true that people can impart some of it, it is not true that another person can impart all of it. Claiming divinity or thinking you're god are both a sneaky trick to get around this and are the basis for some really egregious errors and tragedies. Such people wish to impose their morality on everyone else. People can sometimes come close to imparting knowledge of good and evil, but invariably they will fall short. What I leave out or what your parents leave out or your friends and acquaintances leave out or what your teachers or other authorities leave out must be filled in by the individual's own connection to the Divine, directly.
Incidently, here is where atheism fails. By denying God and the Divine, atheists do not make a divine connection and therefore must make up their morality as they go along and thus they invariably fall short, often much worse than a person who does actually know God and the Divine.
What this monotheistic attempt to define morality amounted to was yet another example of humans falling short. If the original monotheistic writers of their holy books were really serious about helping people to be better, they would have focused on ways to effectively help people make their very own connections to God (and certainly by not requiring some other human go-between) and also how to be less, not more, dogmatically judgmental by teaching them how to compromise and forgive. Admittedly, as monotheism evolved over the last 3000 years there has been recognition that compromise and forgiveness are a better course of action, but no really effective implementation of this recognition has actually been established on any kind of consistent basis, and where it has tried to establish this, regression to original attitudes is a constant problem.
As stated before, monotheism's formulae given for making one's own connection to God and the Divine often fall short (except for prayer, but then, all religion recommends prayer). Improperly or incompletely defining God and requiring human go-betweens falls short. The go-betweens are required because monotheism cannot otherwise define the difference between a real divine being, who imparts knowledge to you somehow non-verbally or even sometimes actually talking to you and its antithesis of being crazy and hearing voices (the imagined voices which can cause one to act crazy or even to commit the most heinous of crimes). The go-between is supposed to tell the difference, but often, and very tragically, fails. Psychiatry secularly attempts to define this conumdrum. It often fails, too.
When it focuses on the negative, monotheism can promote real tragedy such as a woman who kills her children so they can go to heaven and avoid some imagined "hell on earth", or as suicide bombers who kill themselves along with innocent people. The bombers turn reality on its head by making death better than life. This stems from the monotheistic teaching that heaven is better than earth and that you go there when you die. (Originally people thought they went to the underworld when they died and heaven was where the gods lived. Along comes monotheism and says that, instead, you too will be in heaven after you die unless you've sinned without being forgiven--no doubt a great selling point. Of course, this easily could lead to an increase in suicidal behavior (why suffer when you can go to heaven, now) and thus it was necessary to make suicide a sin and against the law--and, that, as we painfully know, doesn't always work!!).
Given the above and considering that monotheism appears to be as nearly judgmental and unforgiving as ever and still is unable to truly recognize its mistakes and contradictions, one is driven to the conclusion that monotheism perpetuates the very problems it seeks to solve and tragically continues to fail itself. It's in a terrible trap.
How to get out of the trap? The problem seems to rest in the conflict between "natural law" and the "laws of men". This "natural law" is a basic morality that most all humans can agree upon and is the basis of all moral agreement. These moral laws are necessary to build the trust necessary for the smooth functioning of human interaction and to enhance human happiness.
Almost everyone can agree that brutality, murder, theft and lying are wrong. This is "natural law". These are eternal moral principles that as Cicero says, "come from the gods" and that "even the gods must obey". The problem rears its head when its seen by humans that there are exceptions, that sometimes brutality, murder, theft and lying are ok. So this is where the "laws of men" can conflict with the "natural law" defined here. The "laws of men" attempt to define the exceptions and so by their very nature create the moral conflict that so bedevils mankind. Defining the exceptions is an endless spiral into finer and finer shades of meaning that creates a climate of moral relativity and confusion. (This is why we absolutely need the Divine as an anchor in the stormy seas of confusion that our minds can create and why we need forgiveness and also why we need to learn forgiveness.)
Since these "laws of men" always seem to be part of any religious or moral system we devise (whether we think so or not) and since if we attempt to eliminate these "laws of men" (and say "God wrote this") we become dogmatic, the various religions will sometimes conflict.
Knowing the Divine, avoiding dogmatism and having a spirit of compromise and forgiveness is the way out.