In the beginning of the play Macbeth is a strong soldier who fights for the King without mercy but his strive for ambition and his curious nature leads him to the witches who give him a prophecy. Banquo realises that there must be a trick hidden in the witches prophecies somewhere but Macbeth refuses to accept that, and when Lady Macbeth finds out about the witches her strong desire for ambition and her cold nature leads Macbeth astray. Macbeth is a little ambitious at first, but Lady Macbeth's far exceeds his and so she is able to get Macbeth to agree with her to kill King Duncan. Macbeth still has a conscience at this stage because he is very hesitant about killing the King but his weak nature over comes him. He has a conscience throughout the entire play as the hallucinations of the dagger and the ghost of Banquo and his vivid imagination see this and his constant worry also provokes him. This is also evident in his terrible dreams which gives the solid theme that he has indeed "murdered sleep".
Throughout the play we see the character of Macbeth change not from just the way he thinks and what we hear from the play, but from the actions he takes in the play, from killing Banquo, then having Lady Macduff and her children murdered, shows the insecurity that was present in Macbeth. After the murder of Duncan Macbeth becomes paranoid and his first step of killing the guards is one of many that Macbeth takes to secure himself. Macbeth is also very superstitious and this is shown when he believes the prophecy the witches told him.
that Banquo's offspring would become Kings.
Macbeth can be summarised into a character although strong physically he is very weak mentally and it is this weakness which causes the downfall and change of Macbeth. Other factors do however also contribute to this change such as his wife whose ambition is very strong at first and is much more stronger mentally than Macbeth but it is also Macbeth's ambition and his trust in the witches which ultimately change him.