The question is:

Why could Winthrop's ideal not be achieved?

The paragraph where I have to find the answer:
Winthrop describes an ideal society, which, if the Puritans had been able to achieve it, would have been a reasonable facsimile of paradise on Earth. Being human, they could not sustain their religious fervor, nor live up to the idealized conditions.

Would the answer be the 1st part of the second sentence or the last part "could not live up to the conditions" or both?

Why not use the entire sentence?

I think the key to this is in the words "being human." What do you think?

So the entire second sentence is the answer?

For my answer I thought being human and could not substain their religious fervor.

But I wasn't sure about the religious fervor part.

Amy~ -- Consider what both Writeacher and I posted. Then reread the question.

What do YOU think?

In order to live in a "paradise," the participants must have religious fervor of some kind.

Unless you live in Lanesville :)