Question

What is the purpose of the witches scenes in Macbeth

Answer 1

There's a few reasons.  But the main purpose is that it represents the struggle between the supernatural and the natural world that is basically the entire purpose of Macbeth. 

Answer 2

The purpose of the witches scene in Macbeth is to create tension by offering audiences just enough information about future events to keep them interested

Step-by-step explanation:

The opening scene with the witches in Macbeth has the purpose of setting the tone of the play and it also foresees future events to happen during the developing of the story, this is also the moment where the witches characterize themselves to the reader as one of the principal motifs in the play.