Quran's Tafhim ( explanation)
*51) In this verse a method of the preaching of religion has been taught, which should be well understood. When a preacher of the truth has presented his message clearly before a person with rational arguments, and has also removed his doubts and objections and answered his arguments, he becomes relieved of his duty of making the truth plain. Even after this if the other person persists in his belief and creed, the responsibility for it does not lie on the preacher of the truth. It is no more necessary that he should pursue the same person, should go on spending his time in discussing things with him, and should make it a point that he has somehow to convince the same one man of the truth. The preacher, in fact, has done his duty; if the other man is not convinced, let hire alone. If the preacher does not any more attend to him, he cannot be blamed for letting a person remain involved in error, because now the other person himself is responsible for his deviation and error.