To know oneself is a personal journey one must travel themselves. You can accompany them to a nearby milestone and/or encourage them to find the next, but ultimately you can’t fight their intellectual battles on their behalf. Expecting to will lead only to frustration.

Note that even in the best case, proceeding will almost certainly alter the dynamics of your relationship, and perhaps end it altogether.

If you’re interested in maintaining the relationship, it would be far better if they were supported in this long journey by a professional (a cognitive behavioral therapist / social worker) rather than a friend/peer. This is especially true for anything so extensive as what you’re describing.

I have found that most people are receptive to a method of periodic open-ended questioning, a common technique of active listening.

I don’t mean confrontational interrogation or leading questions (to which there are “correct” answers). I mean precisely the kinds of unassuming questions someone with more developed introspection might ask themselves internally. Questions of clarification or contemplation, for example, and general curiosity regarding others’ motivations, as well as one’s own.

This method, used carefully, seems to work by temporarily donating perspective to someone, via simple demonstration, which aids them in cultivating their own.

Over time, you may find that they begin to anticipate your questions (perhaps with friendly exasperation) which is the first sign that it’s working.