how to watch Prometheus so it makes sense

Don't worry, I put no spoilers in this post.

The new movie "Prometheus" is beautiful to watch. I recommend seeing it on the largest screen possible. Even with its seemingly incomprehensible plot, the movie is still good simply because of its amazing visuals: costume, set, special effects. They're beautiful to see. The acting is also very convincing. Like with "2001: A Space Odyssey", however, the typical moviegoer will be left with a first impression that goes something like this: "That was beautiful! What did I just see? I don't get it!"

The movie is filled with Christian metaphors. It practically beats you over the head with them. Trying to fit the movie into Christian terms, however, results in confusion. The movie won't make any sense until you take those metaphors back to their original pagan sources. Suddenly, the film elements begin to fit together, and the confusing plot and out-of-character scenes begin to make a lot of sense. I think that the proper mental framework can transform this movie from simply "good" (because of its wonderful visual presentation) to "great" (because of its simple message that transforms fractally into multiple metaphors throughout the film).

To understand the mythical Prometheus and the new movie, we first need an oversimplified crash course in Greek mythology.  Some minor details in this account are very significant to the movie.

• The Greek universe began from forces of nature like Gaia (earth), Uranus (sky), and Pontus (sea). Among their first offspring are the Titans, including the brothers Prometheus and Epimetheus. Later offspring include the Olympians who are typically known as the "Greek Gods". In a war between the Titans and the Olympians, the brothers sided with the Olympians, and they won.
• The brothers visited the earth and formed the clay into creatures. Athena (wisdom, inspiration, civilization) breathed life into the clay, which seemed to take characteristics from its artists, because Prometheus (foresight, ingenuity) created humans who worshiped him, but Epimetheus (hindsight, foolishness) created animals who turned and attacked him.
• Zeus, the leader of the Olympians, was angered by this creation, and he forbade the teaching of civilization to the humans. Athena again favored Prometheus by teaching him so he could pass the knowledge to humanity, which he did. Some time later, at Mecone during a settling of accounts between mortals and immortals, Prometheus tricked Zeus by dividing up the sacrificial bull.  He hid unpleasant bones inside pleasing fat, and Zeus chose this unsatisfying morsel to eat rather than the the other bundle of beef inside the unappetizing bull's stomach. Zeus, again angered, forbade humans from burning wood, and he forbade the gods from giving fire to humans. Prometheus again helped humanity by stealing fire and giving it to them.
• Zeus plotted against Prometheus. He sent Pandora to Prometheus with a gift (not really a box) filled with horrors. Prometheus with his foresight declined the gift. Instead, he gave it to Epimetheus. Pandora lifted the lid of the vessel and released its evils upon the world. She closes it, but the only gift still left inside is hope.
• Zeus punished Prometheus for these continued insults to his authority. Prometheus was chained to a rock where a giant eagle would rip apart his torso to eat his liver. Each day, Prometheus would regenerate, and so the daily cycle of torture would continue. Prometheus suffered intensely for his repeated kindness to humanity.
• Zeus permitted his son Heracles (Hercules) to gain fame by killing the giant eagle and freeing Prometheus.  Zeus insisted, however, that the letter of the law still be obeyed.  A single link was taken from the chain that bound Prometheus, and a chip was taken from the stone to which he was bound.  The chip was laid in the link, and Prometheus was required to wear this new "ring", so metaphorically he was still forever chained to the rock as Zeus had declared.

There are three morals to this story of Prometheus.

1. Intentions are significant. The creation responds to the creator, and ultimately it reflects that intent.
2. Self-sacrifice is the most noble of acts. One can sacrifice others to benefit the self, or one can sacrifice the self to benefit others. A wide moral gulf separates these two methods.
3. Don't anger the gods. They will take retribution, and you are puny next to their might. Your innards are especially tender and tasty.

Now you have the background necessary to understand the film. If you want a deeper explanation (with significant spoilers), I recommend reading either this very detailed post or this much shorter version.

I intend to see the movie again.  Now that I have this extended understanding of the symbolism at play (without being distracted by the Christian approximations of these older motifs), I expect the movie experience to change from "good" to "great".