SPOILERS

Daniel begins the film alone, striking away at the earth, trying to take it for its oil.

Daniel ends the film (relatively) alone, striking away at Eli, trying to take his blood.

Daniel accepts the blood of Christ to win favor from religious interests who control land.

Eli denounces his religious faith to win favor from a businessman who's promised money.

Mary's father beats her because she will not pray.

H.W. loses his hearing because his father's greed pushes him to work the oil so closely.

if religion = business-like ordering of the spirit;

while oil = blood of the earth;

then the blood of man = sacrifice for either religion or business;

and religious fanaticism = corporate greed.

Corporate greed knows no outside convictions, no promise to anything but itself.

Religious fanaticism can justify whatever it deems fit, as it answers and asks its own questions.

Abel Sunday is a version of Daniel Plainview. Both are narrow-minded men, cruel when any suggestion counters their way of thinking. Sunday's ambition for final salvation and Plainview's ambition for great financial success fuels each down a dangerous path. Though both may enjoy the products of their particular faiths for a time--a god-fearing family or a series of well-run oil wells--ultimately, what they seek is always to escape them. Their delusions run deep.

Eli Sunday initially possesses his father's religious tenacity but also longs for Planview's business accomplishments. However, he is still rather immature in the latter department (unwise to the drained Bandy fields and with a string of failed investments behind him). Then, later, he confesses himself a sinner and, though under duress, a false prophet too (that he even allows himself to utter those words demonstrates he is wavering in his convictions).

So, if you have to stand for something one way or another, and if extremism is not the answer, then what? I think we ought to look to H.W. and Mary. Both were raised by stubborn, mean-spirited men, and both found escape in each other; therefore, it's love, faith in your fellow human beings, in their kindness, that shows a way from the tyranny of business and religion.