But I still wonder, why do you open yourself up to his mockery by talking about something he feels distain for?

"What are you reading?"
"Nothing that I think would interest you." (said with a smile).

You know the football/sport advertisements on TV where the guys look "stupid"; why do they sell (beer, teeshirts, whatever)?

If he is immature in that area, don't express your vulnerability there? It's kind of like my girlfriend's dog; she took it to a dog park (large, friendly, Golden Retriever) and a big, mean dog attacked her and her dog did nothing! She decided to take it to training. The first task was to take a strap and "snap" it at/in front of the dog to sort of threaten the do so he growled. The trainer went around and demonstrated with each dog and when he got to her dog and did it, her dog put his paw up to "shake" If you are being disrespected, don't hang around in that "area"?

When he is being disrespectful, I would call him on that, let him know where your boundary is:

"When you said, 'chakras are silly,' I felt disrespected. I believe in chakras and if you are calling what I believe in 'silly' then I feel you are saying that I am silly [to believe in them]. I will not discuss my personal beliefs with you anymore if you do not treat what I have to say with respect." This gives him the option of explaining himself (as opposed to defending himself, which he cannot do because how you feel/felt is how you feel/felt and not something under his control or that he can dispute), apologizing and pledging to do better next time but also puts him on "alert" as to what will happen when/if he slips again.

The next time you are talking and he makes fun of what you are saying, of you, you instantly state, "I cannot allow you to treat me with disrespect, this conversation is over" and you get up and go somewhere else, away from him. Hopefully he apologizes and eventually learns to mind his mouth when later you are talking to him about what is important to you.