The idea Prabhupada said, to be a Guru is not a big thing, he said it is being like a postman ; you have to deliver the message without changing it. You have to be able to understand the teachings of the previous acharyas and deliver them without adding your own opinions and changing it. You have to follow.. you have to be able to train people to follow those teachings and you have to practice them yourself . So you have to be able to teach, you have to follow and you have to be able to train. Person who can do this, then he is an acharya.
His Holiness Jayapataka Swami Maharaj
1986, 30 October, SB class @ New Talavan, USA