Their graces serve them but as enemies - What is the theme of virtue and envy of virtue

Orlando arrives back at Oliver's house and finds Adam there. Adam warns him that Oliver is plotting to kill him by burning down Orlando's lodgings with Orlando inside during the night. I think that virtue is something that Orlando has and his jealous brother Adam knows it. The nature of virtue is developed within the character of the individual. To a man that lacks virtue, the concept is threatening. Adam seeks to destroy (envy of virtue) what he feels he can not have.

Sorry, I meant Orlanado's jealous brother Oliver, not Adam.