What is the ruling on greeting with "peace" (Salam) someone who does not return it and dislikes the Salafi orientation?

Muslims should be loving and harmonious, as Allah Almighty says: "The believers are nothing but brothers." It is forbidden for them to forsake each other without a legitimate Shar'i reason. Therefore, one should seek the reason why the man did not return the greeting. There might be a misunderstanding, or a dislike for the Salafi methodology due to misunderstanding it or due to the actions of some who affiliate with it. One must continue to greet him even if he does not respond, in compliance with Allah Almighty's saying: "Repel evil with what is better, and thereupon the one whom between you and him is enmity will become as though he was a devoted friend."