Answer: Lady Macbeth and Macbeth go through periods of ambition and confidence. Although both experience moments when they feel great amounts of doubt. An example when Macbeth experiences doubt is when he hears the three witches promising his change in power to being king. When he hears this his reaction is to murder King Duncan. Then Macbeth involves Lady Macbeth in his plans to kill King Duncan, where neither of them expresses any sort of remorse or doubt.
Moving past his murder of King Duncan, Macbeth slowly becomes doubtful and begins to feel remorse and guilt for committing the murder of a king. He realizes that Banquo's descendant and family, will immediately remove him from the line of royalty and take away his kingship. This consequence he realizes, causes him to walk in his doubt creating him to act impulsive and destructive.
An example of Lady Macbeth acting in great confidence is when she is sleep talking. She carries the burden of Macbeth's murder on her shoulders. She doesn't realize how it's actually affecting her, by making her sleepwalk. Although she may appear confident and want to seem alright, she instead gives away the secrets her husband tells her, without realizing due to the amount of remorse, guilt, and doubt she has.
