straight and narrow, (walk) the

A morally upright way of life. I need to stay on the straight and narrow so I don't get arrested again.

Fig. a straight and law-abiding route through life. (Referring to a morally rigid and correct course of behavior. Fixed order.) You should have no trouble with the police if you stick to the straight and narrow. Roger was the kind who followed the straight and narrow every day of his life.

COMMON If someone or something keeps you on the straight and narrow, they help you to live a good, honest life and prevent you from doing immoral or illegal things. He now had his faith to keep him on the straight and narrow. Note: You can also say that someone strays from the straight and narrow, meaning that they stop living a good, honest life and do something immoral or illegal. The goal is to prevent them from straying from the straight and narrow. Note: `Straight' was originally `strait', which meant `narrow'. The expression probably refers to a passage in the Bible: `Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.'(Matthew 7:14)

(Follow) the path of virtue. This term probably alludes to the biblical caution, “Strait is the gate, and narrow is the way, which leadeth unto life” (Matthew 7:14), life here meaning salvation. Following the straight and narrow, however, was largely a Victorian concept of rectitude, and the term became current in the nineteenth century. John Dos Passos used it in The 42nd Parallel (1930): “Robbins . . . said that he . . . would have to follow the straight and narrow.”