Indiana Jones and Gandalf

We learn what is essential to know through whatever source is available to us. What we learn is more relevant to who we are in significance than who is teaching.

I will give an example.

In the movie Indiana Jones and the Last Crusade. As the climax is reached, the protagonist (Indy) has to decide which of the Cups is the Holy Grail. He says that despite what popular opinion teaches the cup would not be ornate. In the movie, it ends up that he is correct and gets to save the day. But, what he seemed to have been teaching was how hard it is to make a proper choice. 

Next, we have the example from the Lord of the Rings where the fellowship is sort of trapped in a caved in tunnel and they are looking to Gandalf to determine the correct way. He eventually does so, and Frodo asks him if he instantly recalled by some revelation or something, and Gandalf replies in a way that casts all supposition on a lofty wisdom that he is able to discern the correct way using his own sense of smell, and one way just smells fresher. So, the same lesson is taught to a different audience on how to make a choice between things that are hard to instantly, and are of great consequence.

Both examples teach that discerning truth is best not left to popular opinion or even some supposed mysterious intelligence. I would like to assert that the same is true with religions. Different God's are like different protagonists of a story intended to teach a principle that must be known. And to me, it explains why there are so many similarities. Perhaps, they are coming from the same source (origin) .