Q 16: What is the position of the two testimonies in Islam?
A ---One cannot be regarded a Muslim till he pronounces them. Allah the Almighty says:
The true believers are only those, who believe in (the Oneness of Allah and His Messenger (Muhammad (Peace be upon him)) (An-Nur, 62)
Prophet Muhammad (Peace be upon him) says:
"I have been commanded to fight against people till they testify that there is no god but Allah, and that Muhammad is the Messenger of Allah, perform Prayer, and pay Zakah. If they do that, their blood and property are guaranteed protection on my behalf except when justified by law, and their affairs rest with Allah ", (Bukhari and Muslim)
Reference: 200 FAQ On Muslims Belief - Shiekh Hafiz Ibn Ahmed Al Hakami