Committing sins and acts of disobedience renders Muslim disbeliever.
The Muslim who testifies that there is no god except Allah and that Muḥammad (PBUH) is the Messenger of Allah cannot be declared non-Muslim unless he denies the Oneness of Allah or the prophethood of His honorable prophet Muḥāmmad (PBUH) and other Prophets of Allah. Moreover, a Muslim may always commit sins because he is a human being, and not an angel. Being a human being necessitates that one sins and commits mistakes. Yet, Allah is All Merciful and Oft-Forgiving. It suffice to cite Prophet Muḥāmmad's (PBUH) saying: "By the One in Whose Hand my soul is, were you not to commit sins, Allah would replace you with a people who would commit sins and then seek forgiveness from Allah; and Allah would forgive them". This ḥadīth clearly indicates that a Muslim cannot not be rendered disbeliever due to committing sins, unless he commits them viewing that they are permissible.