Although Macbeth and Lady Macbeth behave in ways that make them appear both butcher and fiend, the complexity of their characterisation and the audience's pity for them makes them appear redeemed by the end of the play.
Malcolm's reference to Macbeth and Lady Macbeth tells the audience how he suffered at their united hands. Whilst the audience feels able to sympathise with him, they have also followed Macbeth and Lady Macbeth's change and humility, allowing the audience to pity them. Both Macbeth and Lady Macbeth are highly complex characters. Macbeth appears loyal and honest on the one hand, but ambitious to the point of ruthlessness on the other. Lady Macbeth speaks intensely about her willingness to perform acts of violence, but is reduced in the end by guilt. Their susceptibility to feeling and conscience - illustrated graphically by the madness induced by guilt - is evidence that they are neither butcher nor fiend.
In Act One, Macbeth is described by his friends and comrades as "brave", "valiant", and "a worthy gentleman". The audience hears of his loyalty to the king, honour, and courage in battle. However Macbeth begins to realise new ambitions shortly after receiving two startling prophecies from the "weird sisters": that he will become Thane of Cawdor, and that he will become king of Scotland. When the former of these becomes a reality, Macbeth begins to wonder what role he will need to take to fulfil the second.
"If chance will have me king, why chance may have me crowned without my stir"
This comment shows that although he is ambitious, he is content for the moment, to leave things up to fate, and is not yet resolved to act against the king. Even when his own wife puts pressure on him to act and...