According to the second view—which holds that his saying, “I testify that none has the right to be worshipped but Allah,” is sufficient for entering Islam—he is a Muslim.
His statement, “If his disbelief consists in denying an obligation or the like,” such as denying the prohibition of fornication, for example, or denying the permissibility of bread, eggs, and the like: in our view, denying an obligation, denying a prohibition, or denying something lawful may all constitute disbelief. So, if his disbelief resulted from denying something of this kind, the author says:
“Then, along with the two testimonies, his repentance requires that he affirm what he had denied.” Thus, if someone denies that prayer is obligatory and says, “I testify that none has the right to be worshipped but Allah, and that Muhammad is the Messenger of Allah,” his repentance is not valid, because he persists in the very matter for which we judged him an apostate. He must therefore affirm, in addition, what he denied—namely, that prayer is obligatory. Whoever does not do so remains in his apostasy.
Likewise, if he denies the prohibition of fornication or wine, while being someone who has lived among Muslims and knows its rulings, and says, “I testify that none has the right to be worshipped but Allah and that Muhammad is the Messenger of Allah,” this is not sufficient for his repentance. For we judged him an apostate only because of his denial that these matters are prohibited, and he still persists in that denial.
And if someone’s disbelief consists in reviling the Companions—may Allah be pleased with them—and he says, “I testify that none has the right to be worshipped but Allah, and that Muhammad is the Messenger of Allah,” but persists in reviling the Companions, he remains an apostate until he ceases reviling the Companions and replaces such abuse with praise.