Choosing a Spiritual Teacher
The closer to truth a spiritual teacher, the more clearly they see, the more readily they will be able to facilitate the knowing of truth in the student. This is the case so long as the teacher can communicate clearly and the student genuinely seeks truth rather than some form of ego-validation.
Given that the student doesn't know truth (hence seeking it), it is impossible for them to accurately assess a teacher's ability to guide them towards it. It's very common to focus on superficial aspects of the teacher - their title, age, gender, popularity, claims, how much they charge, how 'professional' their website looks, how much content they've produced - to make an assessment.
'They've got a long beard, and they're mates with Eckhart, they must know what they're on about'.
If during your search for a spiritual teacher, you find any or many of the following, consider whether they will serve your search for truth or the ego's want for validation:
Ego-bolstering: you're amazing, wonderful, perfect, important, you deserve the world, your scars are beautiful, your vulnerability is a strength, your sensitivity is a gift, you have a right to feel how you feel
Closed-heartedness: you are no one, you are nothing, I will give you the cold, harsh truth about reality
Vague, mystical language: the universe has your back, everything happens for a reason, join our loving, non-judgemental community
Cause and effect: you are experiencing this because of that, x causes y
Blame/powerlessness: they impacted you, they made you feel, of course you reacted that way, forgiveness will set you free
Judgement: good, bad, right, wrong, should, shouldn't
Instruction without context or mention of consequence: meditate for one hour a day, don't drink alcohol, never pee with the door open
Belief: I believe that we are, we aren't, there is, there isn't, I believe in miracles, God, jumanji
Pride: look at me, look at what I know, be proud of yourself, be humble
Weight: this is important, significant, meaningful, this matters, respect and honour me, life, nature, this teaching
If you are drawn to any of the above, then it would be prudent to ask yourself what you are seeking, as it cannot be truth.