Health and religion are closely connected. If someone are capable of following religious principle then health would be Hazard less, every religion offer a pleasant routine for human being.
Religion principle suggest us to live in a happy life. early rise, prayer, seeking work for surviving and come back to family after completing work. All these things suggested by religion.
Mental health is the key of leading healthy life. So religious principle should be followed.
I think they are not connected at any point. Religion is something that we believed in, something we don't know to be true but we know that it is there and we believe it. Religion makes us positive in a natural way making our health affected, but even without religion, we can be positive in our own ways.