Shakespeare was one of the best playwrights who existed during the 16th century. His cunning words have a plain meaning and a hidden meaning. Therefore throughout his play, appearance does not always agree with reality. A limited view on an event or a subject will likely lead to a limited or even false conclusion. For example, the Scottish nobles viewed Macbeth as a "bloody tyrant"; for the readers, Macbeth is not total evil character, but nearly a hero with much physical strength and greatness. Only if he didn't betray his king, he would've been a great thane.
Macbeth is a deranged, old man with flashes of former greatness. He came into the play as a man of honor respected by his fellow soldiers, and has shown great bravery and physical strength, fighting under King Duncan. As reported by the bloody general "Disdaining fortune, with his brandished steel...smoked with bloody execution...carved
out his passage...fixed his head upon our battlement." (I, ii, 15-25) From this quote we can image Macbeth's heroic qualities: courage, bravery and unstoppable. King Duncan greatly praised Macbeth for the Bravery and Loyalty, but what he didn't see from Macbeth's face (Appearance) is the dark desire of Macbeth who is planning to murder the king (reality).
From this point on, as the witches' prophecies come in and Macbeth's ambition aided by Lady Macbeth, this heroic character in both the reader's mind and Scottish noble's mind started its downfall. After the murdered King Duncan, quoted from Banquo "...and I fear thou play'dst most foully for 't." (III, I, 3) all Scottish nobles are suspicious about Macbeth of murdering King Duncan. Ever after, Macbeth seems to believe in his philosophy "things bad begun make strong themselves by ill", (III, iii, 55) and try to cover up his murder...