To preach, teach and dispel doubts is to impart and educate moral concepts, which is currently called "ideological education". This is basic education, and morality comes first. Without a good ideological and moral foundation, you can't become a talent. These three tasks are indispensable for teachers to teach students.

"Preaching" is to teach students a way and point out a direction. "Teaching" means teaching students the methods and skills to go in this direction and this road. "Solving puzzles" means that when students encounter obstacles such as fog and confusion, river separation and natural moat crossing in their walking practice, the teacher gives them some suggestions, reminders or help.

Teaching studies and skills refer to all kinds of technical and theoretical knowledge that can make learners adapt to life and society; Confusion means that people use their knowledge and skills to solve difficulties and puzzles for students when facing unknown things. Preaching, teaching and solving doubts are indispensable. Only in this way can we cultivate good students.