These words‘Kafir',‘Munkir' or‘Mushrik' are no more than statements of fact.
Mushrik(مشرك)(pl. Mushrikūn)(مشركون) One who associates others in worship with God; a
polytheist.
If he a is a magician then he is also a Mushrik[polytheist].
There is no sin greater than shirk, but when the Mushrik repents, Allah turns to him in mercy and forgives him.
Jabeer was a Mushrik at that time, and said:“My heart almost soared,
and that was the first moment that faith entered my heart”.
Thus, the word‘Mushrik' means a person who conceives Allah as infinite
and all powerful but, to use a contemporary parallel, sees Him as the Chairman of the Board with several managing directors, many directors and managers of a mega corporation.
A man guilty of adultery(or fornication)
shall not marry any but the woman guilty of the same or a Mushrik woman, and none shall marry a woman guilty of adultery(or fornication)
but the man guilty of the same or a Mushrik man: such marriages are forbidden to true believers.