What is the best way to say "thankyou"?

Recently I made contact with a very good friend as was at the end of my tether. They have listened to me and suggested a new direction in religion. I have been a believer in the past and today went again for the first time in a long time. I was nervous, but the congregation were really nice and made me feel welcome. I am now convinced that this is the right direction to stay in, but wish to show thanks to the pal whom guided me like the shepherd. Do I need to or do they already know due to their own belief?