What are some ideas for how Shakespeare is positioning the audience to accept the concept of natural order?
King James I, for whom Shakespeare wrote the play, "Macbeth", felt that being king was a position ordained by God and to thwart a king was to attempt to thwart God's plan and God Himself. Shakespeare appeals to this belief in the play.
In Act 1, Lady Macbeth invokes the powers of darkness to help her convince her husband to kill Duncan and to help with the deed itself. The witches, too, are examples of these powers of darkness.
In Act 2, the most obvious example of Shakespeare's use of natural order comes when, immediately after killing Duncan, Macbeth cannot say "Amen". He tells Lady Macbeth that he had most need to say "Amen", but he couldn't. The reason he can't is that he has broken his connection with God by disrupting, or thwarting, God's plan (that Duncan be the king).
When Macduff and the others first arrive at Macbeth's castle the morning after the murder, in Act 2, sc. 3, Lennox claims that the "...night has been unruly..." indicating that there has been a disruption in the natural order of things resulting in "lamentings", "strange screams of death", the owl hooted all night, etc.
Later, in scene 4 of that act, the old man tells Ross that last Tuesday, a falcoln was killed by a mouse and then Ross tells him that Duncan's horses went wild. The old man says he heard that those horses started eating one another and Ross confirms that they indeed, did turn cannibalistic. These are all unnatural acts and they all parallel Macbeth's unnatural act of killing a king.