How to analyze this sentence?

[chaiyu]

Dear Teacher,

I had trouble when I read this sentence in TIME magzine (October 23, 2006, page 41)
Could someone help me?

Here is the sentence:

Fundamentalism is not the only valid form of faith, and to say it is, is the great lie of our time.

Why does this sentence include three "is"?

Thank you!

[BobK]

...

Fundamentalism is not the only valid form of faith, and to say it is, is the great lie of our time.

Why does this sentence include three "is"?

...

Because - in this form - it needs all three. It's not the most elegant of sentences, but it's not ungrammatical. What it's saying is:

'Fundamentalism is not the only valid form of faith. It is untrue to say - though many people do say it - that fundamentalism is the only valid form of faith.'

b

[chaiyu]

Oh, I see.

Thanks for your answer!
It really helps me a lot.