A true Acharya not only preaches dharma but also adheres to it. Gnana and adherence to the rules of the Sastras are both equally important to a true Acharya. These two traits are like the wings of a bird. A bird cannot fly if its two wings are of different sizes. It will lose its balance if there is a disparity in size of the wings.
In the same way, if one does not have proper adherence to the rules laid down by the Sastras, but merely preaches the importance of these rules, then one would be like a bird with two wings, each a different size. Such a person would not qualify to be called an Acharya. A true Acharya, therefore, follows what he tells his disciples to follow. A true Acharya is the one who can guide us to God's feet, said Kidambi Narayanan.
Vedanta Desika says that an Acharya is kinder than even God. God punishes us for our wrongdoings. But an Acharya is more ready to forgive. An Acharya's kindness is unbounded. He is like a cow that yields milk from every teat in its udder.
An Acharya also knows how to correct a person who is erring. He speaks kindly and tactfully to the person, and makes him see the folly of his ways.
There was a person named Pillai Urangavillidasar, who was so enamoured of the beauty of his wife's eyes that he could think of nothing else. Acharya Ramanuja asked him if he would stop thinking about his wife, if he (Ramanuja) showed him a pair of eyes more beautiful than his wife's. Pillai Urangavillidasar agreed, and Ramanuja pointed out the eyes of Lord Ranganatha of Srirangam to him and asked him to observe the beauty of the Lord's eyes.
And from that moment onwards, the man who had been a slave to his wife's beauty became a slave to the Lord's beauty. Now if Ramanuja had said to Pillai Urangavillidasar that since the body was perishable but God was permanent and that therefore he should think of God, then Pillai Urangavillidasar might have retorted that he would give up worldly pleasures in his old age.
Where was the need to do so right away? Ramanuja's tactful handling of the situation earned for Sri Vaishnavism a staunch adherent, who would otherwise have been lost to the tradition.
