straight and narrow, the

the straight and narrow

A morally upright way of life. I need to stay on the straight and narrow so I don't get arrested again.
See also: and, narrow, straight
Farlex Dictionary of Idioms.

straight and narrow, the

The honest and upright way of living, as in He led a wild life when he was young, but he's been on the straight and narrow for some years . This expression is widely though to come from confusion of straight, "not crooked," with strait, "narrow," owing to a misinterpretation of a passage from the New Testament: "Strait is the gate, and narrow is the way, which leadeth unto life" (Matthew 7:14). The current phrase dates only from the first half of the 1800s.
See also: and, straight
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • straight and narrow, (walk) the
  • the straight and narrow
  • fall short of (one's) goal
  • fall short of goal
  • a thin line
  • squeeze into
  • squeeze into (something)
  • fall short of the goal
  • rifle
  • rifle approach