I think it means you are to teach good to student. just kidding.

The Greek person or saying is common to us.
I am sorry about the joke that I write on the subject if it hurt you.
The saying that socrates said is powerful as now as well old.
I like that teaching.

The Greek or this quotation is common to us. The quotation that Socrates once said, is as powerful as well as old saying. I like the teaching. (did you mean Socrates teaching?)

** please add more details, not less than five sentences, because in this way I can check more of your grammar errors and I can also suggest more expressions as what you have been requesting even before Mr. [이름]. **

** what can you say about the quotation? do you agree/disagree? why? do you think it is applicable? **

Thanks!