The ruling on the apostate is the same as the ruling on a disbeliever (kaafir); he may return to Islam by saying the shahaadah, and it is sufficient for himto say it as follows: “Ashhadu an laa ilaaha ill-Allah wa anna Muhammadan Rasoolullah (I bear witness that there is no god worthy of worship except Allah and that Muhammad is the Messenger of Allah).” In order for it to be valid, it is not essential for him to add the words, “wahdahu laa shareeka lah (alone, with no partner).” But it must be noted that uttering the testimony of Tawheed (affirming the oneness of Allah) must be accompanied by sincere belief in the heart and certain faith in what this testimony indicates.