Muhammad is the Messenger of Allah‏

Abu Qatadah Radiyallahu anhu narrates from his father

that Rasullullah Sallallahu alaihi wasallam said:

He who bears witness that there is none worthy of worship except Allah,

and that Muhammad is the Messenger of Allah,

and his tongue frequently recites it

while his heart is contented with it,

the Fire shall not burn him.

(Baihaqi)