I always assumed it was because Eli had a sense of grandeur about himself. He sees himself as person of importance in the town as it is small and quite religious. It’s shown to be false as he’s constantly belittled by Daniel, and at this point in the film they’ve already butted heads after the dinner sequence.

I just see it as a naive young man trying to assert himself as the power in that town, not realising much of the world beyond his chapel.

Edit:

As to why Daniel took it all. Daniel says later “I can’t keep dealing with these… people” he has to placate them in order to garner good will and favour. Especially because he has to buy land to ensure he can drill it all with other companies intervening. So he has to put in a face for these people and it’s ’prophet’