What is the ruling on one who believes that Jews and Christians are not disbelievers, and is he required to renew his Islam by performing ghusl and Shahada? And what is the ruling on one who curses Allah or His Messenger (peace be upon him), and is repentance and regret sufficient, or is he required to renew his Islam? And what are the cases that necessitate renewing one's Islam by performing ghusl and Shahada?

A Muslim is not declared an unbeliever unless the conditions for declaring disbelief are met and its impediments are absent, such as being an adult, sane, acting by choice, and not excused by ignorance or misinterpretation. Whoever doubts the disbelief of Jews and Christians or validates their religion becomes an unbeliever. Jurists have stipulated that whoever doubts the disbelief of a disbeliever whose disbelief is necessarily known is likewise an unbeliever. Ghusl (ritual bathing) is not a condition for the validity of repentance from disbelief; rather, one must hasten to embrace Islam. As for the obligation of ghusl upon embracing Islam, there is a difference of opinion, and the preponderant view is that it becomes obligatory if the disbeliever had done something that necessitates ghusl while in their state of disbelief. The repentance of an apostate and every disbeliever is by embracing Islam and uttering the two testimonies of faith. If their apostasy was due to denying an obligation, then their repentance, in addition to the two testimonies, is by affirming what they denied. Disbelief does not vary with the change of times or places.