When I was in college, I went through a period of earnestly seeking God. I was studying immunology at the time, and realized just how complex the immune system is. It's staggering. Although I did not yet have any connection with a higher power, I found it unbelievable that something so complicated and basic to our survival came from randomness. I had to respect God for that one in a major way. He's the greatest scientist I know.
There are many studies that show a link between stress and immunity. Staying spiritually healthy will help keep you physically healthy. Genetics and environment and mental state are all connected.
Stay well my friends,
Catherine