In act I, Macbeth was confronted with the thought of killing King Duncan and stealing the throne. His soliloquy (I.7.1-28)is his response to the possible actions he is about to take part in. He basically said he felt bad because as his kinsman and his host he should protect him, not kill him. Also the fact that he was such a good king made him hesitate at the thought of killing him. In his discussion with Lady Macbeth after his soliloquy, Macbeth states, "We will proceed no further in this business. / He hath honored me of late..."(I.7.31-32) Macbeth was talking about how King Duncan has honored him recently and how he cannot go through with killing him. Then at the end of act I, Lady Macbeth convinces him to go through with the murder. Then after the murder of King Duncan, Macbeth flips out and begins to rant and rave. He said after the murder talking with lady Macbeth, "To know my deed, 'twere best not know myself."(II.2.73) This showed his extreme guilt and regret of the crime he just committed.
Then, in act III, Macbeth's soliloquy (III.1.47-72) he stated his fears and hatred of Banquo because he was so good. He then called for two murderers to kill Banquo and his son, Fleance. Macbeth needed no motivation for this action other than fear, and he had no hesitation in this decision as with the murder of King Duncan. But after Macbeth knows Banquo is dead, he saw his ghost at his dinner party, taunting him (III.4.40-105). This was a form of his conscience making him feel guilty for what he did. Though his reaction to Banquo's murder is equally as volatile as King Duncan's, the build up preceding the murder shows a stark