Tawhid First

Is it sufficient to merely utter the first pillar: the testimony that there is no god but Allah and that Muhammad is the Messenger of Allah, or are other things required for a person's Islam to be complete?

A: If a disbeliever testifies that there is no god but Allah and that Muhammad is the Messenger of Allah with sincerity, certainty, and knowledge of what this testimony implies, and if he acts upon it, he enters Islam. Then he is required to perform the prayer and the rest of the rulings. This is why, when the Prophet (peace and blessings be upon him) sent Mu'adh to Yemen, he said to him: He did not command them to perform the prayer and pay zakah until after tawhid (the oneness of Allah) and faith in the Messenger (peace and blessings be upon him). If the disbeliever does this, he is given the ruling of Muslims. Then he is required to perform the prayer and the other matters of the religion. If he refuses to do so, other rulings apply to him. If he abandons the prayer, the one in authority calls him to repent; if he repents, well and good, otherwise he is killed. The same applies to the rest of the rulings; he is dealt with according to what he deserves.