Does a Muslim become an infidel due to sin, such as drinking alcohol, for example?

A Muslim does not become an infidel (kafir) by committing a sin unless they deem it lawful (istahlala), and it was unanimously prohibited, like drinking alcohol or fornication, and they knew of its prohibition without any justifiable interpretation or ignorance. Jurists have stated that whoever deems lawful something that is unanimously forbidden, after the removal of any doubt concerning it, becomes a disbeliever. However, whoever deems unlawful something lawful through an interpretation, like the Kharijites who deemed the shedding of Muslim blood lawful, is not judged to be an infidel. Similarly, the Companions who drank alcohol deeming it lawful through an interpretation were not considered disbelievers; rather, the prescribed punishment was carried out upon them.