to reach a higher level of proficiency in one's studies or profession; to attain mastery by proceeding step by step

Literally "to lead a wolf into the house"; refers to bringing an enemy or a dangerous person into one's inner circle, thereby inviting disaster.

a student who has been personally initiated into a craft or school of thought by a master; a disciple who has received the true teachings from a teacher

(idiom) to reach a high level of proficiency or excellence in scholarship or skill; to gradually progress to the highest stage of learning. Literally meaning to 'climb the hall and enter the chamber,' it is also written as [[登堂入室|登堂入室|deng1 tang2 ru4 shi4]].

to use a person's own methods or logic to refute them