His name was Enoch and his father was the priest of the snake cult. The story went that Enoch had killed and eaten the sacred python, and that his father had cursed him.

Mr. Brown preached against such excess of zeal. Everything was possible, he told his energetic flock, but not everything was expedient. And so Mr. Brown came to be respected even by the clan, because he trod softly on its faith.

Based on the context in which it appears, what does the word "expedient" most likely mean in this excerpt from Achebe’s Things Fall Apart?