When you think of the word religion, Judaism, Christianity, Islamic, these are what are called theistic religions. They believe in the concept of a God that created everything. Theravadin Buddhism doesn't have any of this belief, other types of Buddhism I am not sure if they have some belief or not, but when we think of the word religion, it is interesting.
I once read it comes from a Latin word that means to bind one to the highest. Take it for what you want, but is Enlightenment the highest? Buddhism says, yes. The theistic religions say that God is the highest. They are just words, right? But it is a way to purify. In Buddhism, we want to purify our mind and our heart, we want to end all of our anger, all of our greed, our jealousy, we want to purify. There is a part of the Christian Bible that says "The pure in heart will see God." It's very much the same thing if you take the word God out and put the word Dhamma in. In Buddhism, "The pure in heart will see the Dhamma." So we can say that the meditation techniques taught within Buddhism are linked in a sense to the religion of Buddhism. You can't really separate them.
It is nice to know about a tomato. Imagine a tomato, a nice juicy red tomato ready to eat, and you take the skin off and you put the skin here and you have the rest of the tomato here, the big juicy part. Now you see this tomato, the juicy part and the skin, and I say you can eat one of these, which one do you want? Now most people are going to take the juicy part, the inside of the tomato, right?
Now think of this: The skin keeps the inside okay. If I take the skin off put it here and leave the inside here and wait three days, and then I ask you which one do you want to eat, you don't want either one, right? They are rotten. It's the skin that keeps the inside okay. The religion of Buddhism is like its skin. The Monks and Nuns, the ceremonies, the Temples and the scripture books and all, to a certain extent, they are like the skin. Meditation techniques are the inside, they're the meat. That is the real stuff that we want. If you only keep the skin, if you only stay with the skin that is better than nothing, but it is nicer to eat the inside.
Now does it benefit one's health? Yes. When you are angry, what happens to the body? The juices come up and acid in the stomach, you know what anger does to your neck, you know what it does to your teeth. If you are more relaxed, if you are more loving and compassionate, you are just going to have a healthier body. It's just simple because of that difference between a relaxed body compared to a stressed body. I will put a footnote on that, we are not guaranteeing you a perfect body. Even the Buddha got ill a couple times, a lot of the Arahants, people like Sariputta, Mogallana, Ananda, all these people, they also got ill because that was part of their past Kamma fruiting. So Buddhism does not promise a perfect body. It does promise, if you do it well enough, a perfect mind and heart.