Does my belief in the evil eye, and my knowledge of certain people who are known for the evil eye, such that my house is afflicted with misfortune after their visit, enter me into the forbidden Shirk (polytheism)?

Belief in the existence of envy (hasad) and the evil eye ('ayn) is part of a Muslim's creed, and this has been mentioned in the texts of the Qur'an and Sunnah, such as His (Allah's) saying, "Or do they envy people for what Allah has given them of His bounty?" and His saying, "And from the evil of an envier when he envies," and the Prophet's (peace be upon him) saying, "The evil eye is real."

Accordingly, believing in the existence of envy or the evil eye is neither polytheism (shirk) nor forbidden (haram); rather, it is part of the creed. Nevertheless, a Muslim should not be excessively concerned with it or constantly fear it, lest it become an entry point for Satan. Everything is by Allah's decree and destiny, and a Muslim should seek refuge in Allah and fortify himself with Him from all evil, and recite Surat Al-Ikhlas and the two Mu'awwidhatayn when fearing envy or the evil eye.