Answer:
First, I would applaud you for pursing a broad spiritual quest and for being able to see patterns and shared elements in many religions. But Christianity’s claim to being true does not rest solely on a claim of perfect uniqueness. In fact, if it were a perfectly unique religion, it might be so narrow in its ideas and themes that it would be irrelevant to most of humanity. But in reality, Christianity is an international sensation that today covers the globe and is found to be a source of hope, inspiration and peace for over 1 billion people. And it’s growth around the globe in all cultures and races indicates that far from being narrow and irrelevant, it meets universal human aspirations and needs.
You have found that moral codes in religions seems to be universal, and things like the 10 commandments seem to be recapitulated in the morality of other pagan groups. I agree! Now, your assumption is that this is some kind of problem for Christianity being true. It’s just the opposite. For many years the assumption of sociologists was that morals are subjective, culturally driven, inventions of natural selection. Therefore, what is “right” they said, was different between human cultures. Your own research and that of others has found the opposite is true. Namely that although on the surface moral codes may vary, at their core, the principles are universal. (See the appendix in “The Abolition of Man” by CS Lewis for a listing of those universal moral principles found around the world).
So yes, the morality of the Bible is not unique and this is really a mark in it’s favor because it means that the standard by which God will judge the world is EXPLICITLY known in all corners of the world. Wouldn’t we expect that if Christianity were true that the God who gave the moral code to Moses is the same God who made and loves the Egyptians, the Greeks, and Native Americans? Should we expect that the moral code given to help us live righteous and prosperous lives, and by which he would judge us should be known to only one tribe? Of course not.
Romans 2:14-16 affirms this very idea, saying EVERYONE has a law, even if it's just their conscience. By affirming that these moral laws are very similar, the agnostic cuts off the limb he sits on: namely that human morality is relative and therefore no proof of the existence of a Moral, Law-giving God. In discovering that all morals are fundamentally the same, you’ve uncovered one of the key evidences that morality is undeniable REVELATION of God's existence and character to all mankind. It flies in the face of pure naturalism, it contradicts any ethics (if we could call it such a thing) that we would ever predict could arise randomly from the primordial soup by the survival of the fittest.
The same is true when you mention the reoccurring theme in religion of the dying and rising god. The fact that these myths are found outside Christianity is actually evidence for why the Christian story is really GOD'S story, and that right relationship with God must be found in the way Christians say it is. CS Lewis called this type of revelation, "good dreams". Doesn’t it make sense that if God was truly at work in the work of Christ, then this God should be interested in laying the foundation for the acceptance of this work, not only in giving the moral law in our hearts, but also by these embedded stories all over the globe? This shows to me the fairness of God, and the accessibility of his salvation offer AND the superiority of Christ over all other "ways".
CS Lewis said, Christianity does not repudiate paganism, it fulfills it! In fact, one of the tipping points in Lewis' conversion from atheism was when a hardened atheist friend said to him (I’m paraphrasing): "you know all those legends of the dying and rising god? I've been looking at the NT in a fresh way and it looks like it might have actually happened, once." I say Christ is proved superior to these pagan dreams not because they are evil, and he is good, but simply because they are the shadow and Jesus is the reality. Jesus’ story is history not myth.
Now, this is where we may part company. Perhaps you put the Christ story along side these other stories... But I believe no fair look at the data can maintain that stance. Look at the myths and then look at the NT... The myths are "once upon a time." The NT is "in the year Augustus was Caesar, in the time Quirinius was governor of Syria, when Herod was Tetrarch." The NT may be untrue, but one thing it's not: a myth. It's a story located in history, with names of people who really lived, and can be corroborated by external sources, and examined for historical accuracy. Geographical locations, dates, names are PACKED into the story, and many such details can be verified. A myth? No. A polemic? Yes. It's core idea lied about? Possibly. But a myth? No!
Joseph Campbell and others maintain that this story was corrupted by Mithraism. Mithraism was a bull cult where the members had some kind of blood baptism and where the mythical god dies and rises. Many parallels are made to Christianity, but what you find under examination (and if you don't have an a priori agenda of trying to reduce Christianity into just another mystery cult) is that any parts of Mithraism that look like Christianity came AFTER Christianity was established. Parts of the cult which date to BC show almost no similarity to Christianity. So it begs the question, if one borrowed from the other, which way did the borrowing it go? Most likely, Mithraism borrowed from the growing Christian movement.
So again, I'd affirm the Hero myths as signposts POINTING to the Reality. These things were shadows, but Jesus was the real deal.
Christians affirm there are many truths inside of systems that are not explicitly Christian. You may have been led to believe it’s either/or and Christianity is either all different and true or all the same and untrue. But what if other religions are not all false, but contain elements given by God to point people to his ultimate Answer? See Acts 17:26-28.
