Question On The Sentence Below.

[PedramT]

First, can I start a sentence with but?
Second is the ; right or should I use : instead? (after subjects)

But know we are the one who narrowed their perspective on one of the most important human subjects; religion and faith.

[woofgang]

Formally no, you can't start a sentence with "but". But informally loads of people do. (see what I did there?) If you are using a plural (we) then you need to make "The one" agree with it and change it to "the ones". Using "one" twice is a bit lumpy anyway....you might change the first use to "people who"....or better, I think, to shorten the sentence by changing "one of the most" to simply "a" The semi colon....hmmm

[Old_Geezer]

Officially you ought not as it is a word that continues the existing sentence. But I do.

Particularly if the already existing sentence is a long one, I reckon that the reader deserves a long pause.