How is Orson Welles's character Macbeth different from Shakespeare's Macbeth?

This film version is extremely different from the play in a number of ways. For example, all of the Porter’s racy lines had to be cut, censorship being super strict in the 1940s. Moreover, the character of Donalbain is removed altogether and many lines were edited or reassigned. Welles had chosen to add a character, the Holy Man, whose purpose, according to the director and star, was to portray the battle between the ‘old’ religion (Paganism) and ‘new’ religion (Christianity).