Is meditation "spiritual"?
The simple answer is no, it isn't.
Now for the longer answer and the reason why it isn't.
Let's try to understand this with a thought experiment. 1,000 years ago, the notion of spirituality - in what way do you think it existed in the world? It was a term maybe used by religious organisations. Now think back 10,000 years ago, before there were any modern, developed human societies. In what way do you think the word "spirituality" existed? There probably wasn't a word or a language for it! Now think back 100,000 years ago - was there even any humans then? What about 1,000,000, or even 1,000,000,000?
Do you see where we're going with this?
"Spirituality" is invented by the human mind
With the above example, it's clear to see that the human mind is the inventor of such terminology, but in fact, everything is all just one. I know, I know I can hear you right now:
"everything is just one" is such a spiritual term!
It may be something that is predominantly used in spiritual circles, but it's not to say it is a strictly spiritual term! In science, Albert Einstein alluded to this oneness with his ground breaking formula e=mc2 and in Quantum Mechanics, they refer to this one existence as the Quantum Field. Are either of these 2 things "spiritual" or are they "scientific"? We would argue that they are neither, and both are just conceptions formulated by the human mind.
Whether the Earth exists, it is still just that infinite oneness. Whether the solar system exists, it is still just that infinite oneness. Whether all the celestial bodies in the infinite sky exist, or all people exist, it is still just that infinite oneness!
The infinite oneness has many names
Depending on where in the world you are, this existence has many culturally derived names. Christians call it God. Muslims call it Allah. Buddhists call it Buddha. Scientist call it Energy and Light. Spiritual people call it Spirit and Soul. Atheists call it Universe. Some call it emptiness, some call it just life, and some have no name for it simply referring to is as Nothingness. Whatever name you want to give it, the name is not important!
What's important is that existence exists within you. There is not a single thing in that eternal and infinite existence that isn't part of it and wholly one with it. We are all one with it, and all a part of it. There is no separation whatsoever.
After Einstein, it was commonly believed that light was the fastest object in the Universe. However, even during his time there was the discovery of what is now referred to as "quantum entanglement" which is the ability of an object, sharing a condition or shape to be entangled through time and space. When one half of the object is altered, across time and space, the other part is instantaneously altered as though they weren't separated! Einstein famously dubbed this "spooky action at a distance".
So is meditation "spiritual"?
This all sounds a lot like "woo woo" to me!
I can hear your scepticism right now, and you know what? I don't blame you! It's not something we can come to know from within our rational mind. This is where meditation comes into it.
Meditation is about finding that existence within you. It doesn't matter what name you want to give it. The fact is irrefutable - that it exists within you. And through the meditation of discarding your mind world that overlaps this existence, you too can find and discover this existence for yourself. Once you discover it, there is nothing anyone can ever say to persuade you of this one fundamental truth. That we are all one.
What could be more beautiful than this?