The Aztec worship of their sun god was rather barbaric because humans were sacrificed to the god. The rationale for this sacrifice had to do with Aztec myth, which held that the sun god sacrificed his very own blood to create the Earth and generate the life that is upon it. This meant that everyone–absolutely everyone–owed an enormous debt to this god, and only human sacrifice–the most dear fruits of ourselves–could ever do as a gesture of gratitude and repayment. So Aztec religion functioned on a guilt trip. The sun god did something really big for you, and you ought to do something really big for him. It was all about expressing gratitude in a highly theatrical and traumatic way, so as to receive the god’s notice and ongoing blessing and approval.
Then I thought of the Christian narrative, and how it functions in much the same manner. In other words, I thought, “How like Aztec religion is Christianity!”
As with the Aztec god, in Christianity, Jesus sacrificed for your life (“Jesus had a really bad weekend for your sin”). Now you are expected to sacrifice your life to Jesus. You are in Jesus’ debt, and to express your gratitude, you may not be called upon to die on a literal altar in the next moment, but you are to present yourself to Jesus as a sacrifice in each moment. You are to hijack your own purposes to his purposes, which amounts to a kind of death in life. You might even be expected to act as a martyr for him, literally going to death on his behalf should such a circumstance present itself.
Maybe this is part of the reason that passion plays (and Mel Gibson’s infamous film) have such a powerful effect. People are reminded to feel guilty over what Jesus did for them. To watch Jesus die so traumatically for you is to impress upon the mind and heart gratitude and thanksgiving, which you can now reciprocate.
And this psychological frame of mind can then get tied up with politics, and seized upon by Machiavellian rulers, as happened in the Aztec theocratic state. Religion got put into the service of power. And as with the Aztec state, so with (for example) medieval papal states. The state benefits when its subjects renew their commitment to sacrifice themselves to the collective culture’s god, for it puts them in mind to also sacrifice to the deity’s representatives on Earth, which are clergymen and politicians. It means the sacrifice of the subjects to god and state; the god wed to the state–which means its subjects are meat for the state.
Clever. As in chiming with meat cleaver.
So it puts a different spin on Thanksgiving, doesn’t it? The pardoning of a turkey by the American President, the collective prayer, and the whole Thanksgiving cultural ritual generally seem designed to pluck ever so softly on the sorts of gratitude strings in people that religions and theocratic states (historically) have plucked much more dramatically. With the sacrifice of 40 million or so birds in a single week–a symbol of God’s sacrifice for us and his bounty brought to us–it sets up the state to get in on the act by “pardoning” one bird from its fate (the other birds died that we and that single bird might go on living).
And it makes some of the remarks that Abraham Lincoln made, on the initiation of Thanksgiving as a national holiday in 1863, sound all the more like those which might have been spoken by an Aztec priest:
The year that is drawing towards its close, has been filled with the blessings of fruitful fields and healthful skies. To these bounties, which are so constantly enjoyed that we are prone to forget the source from which they come, others have been added, which are of so extraordinary a nature, that they cannot fail to penetrate and soften even the heart which is habitually insensible to the ever watchful providence of Almighty God. In the midst of a civil war of unequaled magnitude and severity,… [p]opulation has [nevertheless] steadily increased, […] No human counsel hath devised nor hath any mortal hand worked out these great things. They are the gracious gifts of the Most High God, who, while dealing with us in anger for our sins, hath nevertheless remembered mercy. It has seemed to me fit and proper that they should be solemnly, reverently and gratefully acknowledged as with one heart and one voice by the whole American People. I do therefore invite my fellow citizens in every part of the United States, and also those who are at sea and those who are sojourning in foreign lands, to set apart and observe the last Thursday of November next, as a day of Thanksgiving and Praise to our beneficent Father who dwelleth in the Heavens.
No human sacrifices now, but touching upon the same family of human psychological impulses and superstitions. All those poor turkeys.
Prometheus Unbound 
Interesting thoughts. We have not really become civilized as we think