I read somewhere that some Shia have said that the as both Ali and Muhammad are from one light that they are one person. Elsewhere, that Muhammad comes from God's Light, and his Light is uncreated. It seems like we are on the same page, the difference being where we draw the distinction of the term 'God'. In the Trinity, the father alone has no origin, the Son and Spirit come from Him, while remaining within Him, before time began and both being uncreated. However, if the term 'created' is stretched to include origin, then you can see how differences of opinion can form an apparent difference of dogma. Everything was created via the Son and Spirit in Christianity, and through the Light of Muhammad in (sufi) Islam: hence uncreated. So it appears that the Muslims keep the term God for what we call unoriginate (i.e. the Father), we use it for the Creator (which includes creating through the Son in Christianity, or through the Light of Muhammad in Islam). Then again, some sufis have spoken of Allah-Muhammad.