They believe him to be a very significant prophet, the prophet before Muhammad came to reveal the Quran. Now for a practicing Muslim, there are often considered to be five pillars. And this is especially the case for the majority of Muslims, for Sunni Muslims. Shia Muslims have a slightly different combination of pillars, but there's a lot of commonality. So the five pillars, the first is this notion of faith, which is referred to as shahada. Shahada can also be interpreted as testifying or testimony. And it's this notion that a Muslim needs to believe and say that there is no God but God.