The kind of teaching that Paul had in mind is not the mere imparting of knowledge. Effective Christian ministers reach the hearts of people and motivate them to make changes in their lives.
اُعْكُفْ عَلَى ذٰلِكَ ،‏ فَإِنَّكَ بِفِعْلِكَ هٰذَا تُخَلِّصُ نَفْسَكَ وَٱلَّذِينَ يَسْمَعُونَكَ أَيْضًا » .‏