Final answer:
The difficulty Macbeth expresses in saying 'Amen' after the murder symbolizes his guilt and moral turmoil.
Step-by-step explanation:
The difficulty Macbeth expresses in saying 'Amen' after the murder symbolizes his guilt and moral turmoil. In the play, Macbeth has just committed the act of regicide by killing King Duncan. The difficulty in saying 'Amen' reflects his deep remorse and the psychological impact of his actions. 'Amen' is a word used in prayers to affirm belief and express agreement, but Macbeth's inability to say it shows his inner conflict and the disconnection between his actions and his faith.