In Shakespeare's tragedy Macbeth neither the Lady nor Macbeth himself is ever able to reach a compromise with their guilty consciences. And the results are fatal for them both.
A.C. Bradley in Shakespearean Tragedy demonstrates the guilt of Macbeth from the very beginning:
Precisely how far his mind was guilty may be a question; but no innocent man would have started, as he did, with a start of fear at the mere prophecy of a crown, or have conceived thereupon immediately the thought of murder. Either this thought was not new to him, or he had cherished at least some vaguer dishonourable dream, the instantaneous recurrence of which, at the moment of his hearing of prophecy, revealed to him an inward and terrifying guilt. (316)
In his book, On the Design of Shakespearean Tragedy, H. S. Wilson comments regarding the guilt of the protagonist:
It is a subtler thing which constitutes the chief fascination that the play exercises upon us - this fear Macbeth feels, a fear not fully defined, for him or for us, a terrible anxiety that is a sense of guilt without becoming (recognizably, at least) a sense of sin. It is not a sense of sin because he refuses to recognize such a category; and, in his stubbornness, his savage defiance, it drives him on to more and more terrible acts. (74)
Blanche Coles states in Shakespeare's Four Giants that, regarding guilt in the play:
Briefly stated, and with elaborations to follow, Macbeth is the story of a kindly, upright man who was incited and goaded, by the woman he deeply loved, into committing a murder and then, because of his sensitive nature, was unable to bear the heavy burden of guilt that descended upon him as a result of that murder. (37)
In "Memoranda: Remarks on the Character of Lady Macbeth," Sarah Siddons mentions the guilt and ambition of Lady Macbeth and their effect:
[Re "I have given suck" (1.7.54ff.)] Even here, horrific as she is, she shews herself made by ambition, but not by nature, a perfectly savage creature. The very use of such a tender allusion in the midst of her dreadful language, persuades one unequivocally that she has really felt the maternal yearnings of a mother towards her babe, and that she considered this action the most enormous that ever required the strength of human nerves for its perpetration. Her language to Macbeth is the most potently eloquent that guilt could use. (56)
Clark and Wright in their Introduction to The Complete Works of William Shakespeare explain how guilt impacts Lady Macbeth:
Having sustained her weaker husband, her own strength gives way; and in sleep, when her will cannot control her thoughts, she is piteously afflicted by the memory of one stain of blood upon her little hand. (792)
The Tragedy of Macbeth opens in a desert place with thunder and lightning and three witches who are anticipating their meeting with Macbeth. Macbeth is greeted by the witches...