Trying to teach an old dog new tricks, very difficult to do. Changing a person is a very challenging thing, especially when cognitive dissonance is involved. Many do not want to let go of beliefs, habits, etc. because they can not see past those attachments to a greater good on the other side. It is not impossible but it will take compassionate work that does not come off as being a controlling person.
I can relate to this when I want to help someone convert their life to Jesus. If I am pushy and preachy, controlling and ego driven they will not even hear me. I approach them is a loving way, never being pushy, only pointing them in the right direction. Many of these people simply can not let go of their secular beliefs so they remain unchanged.
So with any belief system there will be a certain degree of resistance and to get through that resistance one needs to let go and put there trust in a new way of living.