Why do jinn enter Muslims and not disbelievers?

The jinn can possess a human, whether Muslim or disbeliever. Sheikh al-Islam Ibn Taymiyyah limited the reasons for a jinn possessing a human to three: the jinn's love for the afflicted person, desiring to enjoy them; the human harming the jinn; or mere mischief. These reasons do not differentiate between a Muslim and a disbeliever.

Whoever does not believe in jinn possession may treat the matter as an organic or psychological illness, and this is common among disbelievers.