Then he said, "One must take the firm attitude: 'What? I have chanted the Mother's name. How can I be a sinner any more? I am Her child, heir to Her powers and glories.'
"If you can give a spiritual turn to your tamas, you can realize God with its help. Force your demands on God. He is by no means a stranger to you. He is indeed your very own.
"Again, you see, the quality of tamas can be used for the welfare of others. There are three classes of physicians: superior, mediocre, and inferior. The physician who feels the patient's pulse and just says to him, 'Take the medicine regularly' belongs to the inferior class. He doesn't care to inquire whether or not the patient has actually taken the medicine. The mediocre physician is he who in various ways persuades the patient to take the medicine, and says to him sweetly: 'My good man, how will you be cured unless you use the medicine? Take this medicine. I have made it for you myself.' But he who, finding the patient stubbornly refusing to take the medicine, forces it down his throat, going so far as to put his knee on the patient's chest is the best physician. This is the manifestation of the tamas of the physician. It doesn't injure the patient; on the contrary, it does him good.
Source: gospel of Sri Ramakrishna