330. Amīr al-mu’minīn, peace be upon him, said: The least right of Allāh on you is that you should not make use of His favours in committing His sins. 
 There are a few grades of denial of favours and ingratitude. The first is that a person may not be able to appreciate (the real significance of) a favour; for example, the sight of the eyes, the speech of the tongue, the hearing of the ears and the movements of the hands and feet. These are all favours bestowed by Allāh but many people do not realize them to be favours, and do not entertain feelings of gratitude. The second grade is that a person may see a favour and appreciate it but may not feel grateful for it. The third grade is that a person may oppose the Bestower of the favours. The fourth grade is that instead of using the favours granted by Him a person may use them in committing sins against Allāh. This is the highest grade of denial of favours.