Indeed, the reality is that when the very same ardent beseeching practiced by the grave-devotees is undertaken by those who are truly sincere to Allah, the sincere are seldom turned away, whereas the grave-seekers themselves are seldom answered. Concerning the sincere, the Prophet ﷺ said: “No servant calls upon Allah with a supplication that contains no sin nor severing of kinship without Allah granting him one of three things: He either hastens the fulfillment of his request, stores up for him an equal measure of good, or averts from him an equal measure of evil.” They asked, “Messenger of Allah, then we shall make many supplications!” He replied, “Allah has even more.” Thus their prayers are an unceasing source of good.
As for the grave-devotees, on the rare occasions they are answered, a person finds his affirmation of divine oneness weakened, his share from his Lord diminished, and his heart deprived of the taste and sweetness of faith once enjoyed by the earliest believers. Seldom is any blessing placed in the need that was met—unless Allah pardons them because they do not realize that this practice is an innovation. For when someone strives to reach the truth and errs, Allah rewards him for his effort and forgives his mistake.
The same holds true for every practice people imagine has influence over the universe while the Law declares it forbidden—such as astrological conjurations, psychic projections like casting the evil eye, and other unlawful invocations.