Is the partial ritual bath (ghusl mujzi') from major ritual impurity (janabah) sufficient for an apostate? And what is the ruling concerning someone who committed an act that nullifies Islam (naqidan min nawāqid al-dīn), most likely before puberty, and was ignorant of its ruling, then prayed and memorized the Quran? And what is the ruling concerning someone who performs the ritual bath (ghusl) and pronounces the Shahadah to embrace Islam every now and then? And is their overcoming of the whispers of disbelief (waswās al-'aqīdah) an indication of their Islam?

It is clear from the question that the questioner is afflicted with waswasah (obsessive whisperings), and they must turn away from these whisperings until Allah removes them. A disbeliever is not required to perform ghusl (ritual bath) upon embracing Islam, unless they committed an act that necessitated ghusl while they were disbelievers. If the questioner is certain that they committed an act that nullifies Islam, this does not harm them as long as they repented to Allah and became steadfast in their religion, for the one who repents from a sin is like one who has no sin. It is not prescribed for a person to excessively perform ghusl and utter the Shahadatain (declaration of faith) in response to waswasah. Rather, they should know that they are a Muslim, and their dislike of the whisperings is a sign of the sincerity of their faith.