A true guru is always thinking for the welfare of others, whereas a false teacher is always thinking for his or her own personal gain or even of destroying others. A true teacher does good even to those who do him or her harm. Just like the sandalwood tree: if anyone cuts into the tree, even still, the tree gives forth its beautiful fragrance. The saintly being is always engaged in striving for the upliftment and welfare of everyone. An unsaintly being is known by the capacity to do harm to others and do harm even to himself in the process.