(125) “Invite to the way of your Lord with wisdom and gracious counsel, and debate with them in the best manner. Surely your Lord knows best who has strayed from His way, and He knows best those who are rightly guided.”
That is: Let your call to all people, Muslims and unbelievers alike, be to your Lord’s straight path, which comprises beneficial knowledge and righteous deeds, “with wisdom.” This means addressing each person according to his condition, understanding, views, and receptiveness.
Wisdom includes calling with knowledge, not ignorance; beginning with what is most important, then what follows in importance; presenting what is easiest for minds to grasp and understand and most likely to be accepted; and proceeding with gentleness and kindness. If he responds to this wise approach, then that is sufficient. Otherwise, move on to calling him through gracious counsel: commands and prohibitions accompanied by encouragement and warning.
This may be done by explaining and enumerating the benefits contained in the commands and the harms contained in the prohibitions; by mentioning the honor granted to those who uphold Allah’s religion and the humiliation of those who do not; or by mentioning the rewards Allah has prepared in this world and the Hereafter for the obedient, and the punishments He has prepared in this world and the Hereafter for the disobedient.
If [the person being called] believes that his position is the truth, or if he is himself calling to falsehood, he should be debated in the best manner. This means employing the methods most likely to elicit a favorable response from him through both rational and revealed proofs. One such method is to argue from evidence that he himself accepts. The debate must not descend into quarrelling or exchanging insults, thereby defeating its purpose and yielding no benefit. Rather, its aim must be to guide people to the truth, not to prevail over them or anything of that sort.
His words, “Surely your Lord knows best who has strayed from His way,” mean that He knows the cause that led him into misguidance, as well as the deeds resulting from his misguidance, and He will recompense him for them.
“And He knows best those who are rightly guided”: He knew that they were receptive to guidance, so He guided them; then He bestowed His favor upon them and chose them.