谤师、捨师，势必无尽期堕落地狱
《菩提道次第甘露藏》中说：后世无已漂恶趣

在我们和师长建立法缘之后，本着师生关系的认知---甚至只是获得一句咒语几个字母的口传，或者教法中的一首偈颂---无疑地，最重大的恶业是毁谤或舍弃上师。

节录来自《师心佛心》

The harm of not relying on the teacher  

It is inevitable for one to fall into hell endlessly for slandering, and abandoning the teacher.

It is stated in The Essence of Nectar - Stages of the Path of Englightenment that, one will drift in miserable realms endlessly.  

After we have established a dharma connection with our teacher, where the teacher-student relationship is founded on just a mantra with few words that was taught verbally, or with only one verse of the teachings given, it is without a doubt that abandoning or slandering the teacher is of the weightiest nonvirtuous karma. 

Translated from the excerpt from The Heart of the Path