What is spiritual?
The word spirit is often defined as non-material. However, when we say what something is not, we do not really say what it is. A better definition is that which makes an intelligent being what it is. At least because it is positive. However, we are aware of non-material things in everyday life.
What is a person?
When we ask, what is the person, say John, we do not mean the body because although we do not normally encounter John without the presence of the body, we do not consider the body to be John.
When we look at a dead body, it really seems as if the person has left. And when a person is radically different from how they usually are, or how we knew them, we say they are not themselves, or even they are not the same person.
The non-material in everyday life
When we say that someone is intelligent, we do not mean they possess some thing or some part of them is their intelligence. We never expect a surgeon to proudly announce over a piece of John that this thing is his intelligence. Intelligence is not a thing and appears to be non-material.
Similarly, other qualities we use to describe a person such a lively, happy, brave, and so on, do not appear to be things, but qualities of the spirit.
In the same sort of way, a stone rolling down a hill is not the same as one that isn't moving. Yet the moving stone does not possess some thing which it does not possess when it is stationary. Physicists say it possesses kinetic energy. Also electricity passing through a wire can cause machines to work. Yet in both cases there seems to be something that is not material in any normal sense. When physicists talk about the quantum world, they seem to give up on anything material at all! They begin to talk like Eastern mystics!
The non-material seems to be a real thing in our everyday lives. And when we use the word spirit, we talk about that thing which is the animating force in nature but which appears to be non-material.
Spirit is therefore something like this, which is non-material, but also intelligent or sentient.
The mind is also non-material, but we do not equate the mind with the spirit. We tend to equate the spirit with the person and the mind is something, which is non-material, which the spirit possesses.
The mind and the brain are not the same thing. Sometimes we mistake them, but only when we aren't thinking clearly. We sometimes say that someone has a good brain. But the brain they have is indistinguishable from anyone else's brain. There was nothing about Einstein's brain which distinguished it from other brains.
When a brain is damaged, it sometimes, but not always, affects the mind. But when the brain is whole, it does not tell us about the person. Just as a master pianist could not play a wonderful piece of music if his or her piano was broken, even with the best piano in the world, I could not play a note!
We need a brain to think, but even the best brain in the world is no good to a dumb spirit! Even people with damaged brains are sometimes very intelligent!
It appears that the non-material is commonplace in everyday life, and it appears that the person is something non-material, but the big question is can the person exist apart from his or her body?