Macbeth is shown as a courageous warrior at the beginning of the play, and he remains courageous until the very end. This is his most admirable quality. He might have even defeated Macduff in their final combat if he hadn't been demoralized by hearing Macduff say that he was "from his mother's womb untimely ripped." Macbeth had thought that no man born of woman could ever defeat him. He demonstrates his admirable courage by even challenging Fate itself, first in Act 3.
For Banquo's issue have I filed my mind,
For them the gracious Duncan have I murdered,
Put rancors in the vessel of my peace
Only for them, and mine eternal jewel
Given to the common enemy of man,
To make them kings, the seed of Banquo kings!
Rather than so, come, Fate, into the list,
And champion me to the utterance! (3.1)
Macbeth believes that Fate had decreed that Banquo will be the sire of a line of Scottish kings. Nevertheless, Macbeth will not have it so. He and his wife both feel that it is fruitless to become rulers unless they can pass the crowns on to their own offspring. Macbeth defies Fate itself by plotting to murder both Banquo and his son Fleance, thus eliminating the entire line of kings chosen by Fate. He is only partially successful. Banquo dies but Fleance escapes.
Then when virtually alone on the field of battle and confronted by his nemesis Macduff, Macbeth shows his superhuman courage by challenging Fate again.
Though Birnam Wood be come to Dunsinane,
And thou opposed, being of no woman born,
Yet I will try the last. Before my body
I throw my warlike shield! Lay on, Macduff,
And damn'd be him that first cries, “Hold, enough!” (5.7)
These are the last words spoken by Macbeth. He refuses to yield. We have to admire him for this quality even though we have come to despise him for all the wicked things he has done.