Gyalwang Karmapa on the first day of Gyalwang Karmapa’s Lineage Practice Teachings
"Gampopa mentioned three characteristics of a genuine lama.
A person who could only focus on this life was not a genuine dharma practitioner. A dharma practitioner should think of future lives and the path of liberation.
The second characteristic of a lama was that they could guide their students with their great wisdom; without wisdom and intelligence a lama was unable to teach the dharma to a range of students with different needs.
The third characteristic was endowment with great compassion, so that a lama never gave up on their students, supporting them however bad they were. Without this great compassion, a lama might well abandon a very difficult student. The ideal was that a lama would want to keep their students from falling into the lower realms, even at the cost of his or her own life.
In short, a lama’s good qualities should exceed their faults. An uneducated person able to help students focus on the dharma and future lives, could be a lama, in the same way that a mother who loved and cared for her children tried to pass on her best traits to them, in spite of her lack of education.
Then how could a student assess a lama’s qualities?
Gyalwang Karmapa warned that, except for a few extraordinary individuals, it was very difficult to assess a person’s qualities, and impossible to know what they were thinking, so the only method was to observe the lama’s words, deeds and conduct, checking that they were in harmony, and that they did not contradict the dharma. Although a skilled imposter might fool people for a short time, they wouldn’t be able to fool all of the people all of the time!"