The phrase "straight and narrow"

Surely, you've heard the expression. People say things like "Stick to the straight and narrow, and you'll be safe!" I wondered where the phrase came from and ferreted around on the internet to learn the answer. It comes from the bible. (Horrors!) The following appears in the King James version:

Enter ye in at the strait gate: for wide is the gate, and broad is the way, that leadeth to destruction, and many there be which go in thereat:

Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.

Kinda kills the urge to use the phrase. But it's always good to know where a phrase comes from -- if only to avoid it in future. While we're at it, I guess it should be spelled "strait" rather than "straight". It refers to a strait, a relatively short waterway that connects two bodies of water.

Come to think of it, "Strait is the Gate", the book by Andre Gide, is spelled that way. I loved this book when I was a teenager. Anyway, phrase origin solved. We can put it up on the shelf now and let it get dusty.