First, Mahayana masters must have uncontrived bodhicitta. According to the sutras, if a person has uncontrived bodhicitta, although he or she may not be perfect in every way, we can take this person as our master when no other teacher can be found. We become disciples in the hope of receiving from the master the wisdom and skillful means conducive to our liberation, nothing else. If the master has uncontrived bodhicitta, he or she will at the least instill something good into our minds. In other words, the master will not use us for personal gain, and will try to the extent possible to guide us. So we can learn something.
~Depicted from GATEWAY TO VAJRAYANA PATH - Vajra Master and Empowerment