Why?

The original first century Christian Symbol was a fish with a stick figure walking out of it's mouth. It was called the Sign of Jonah. It represented a spiritual rebirth. Notice that it wasn't a man walking out of a cave like Jesus. That would have been misinterpreted, and it was ultimately.

A cross, inside a circle, with a diagonal line through it.

Darwin name in a fish outline? Ichthus spelled in Gk. in the same?

Be Careful because enemies often enough end very similar!

I don't get where this thread has lead. A global symbol to represent atheism and non belief in religions is one thing; but there is talk here about Buddhism, celts, and mystical what not. The original poster expressed himself a little loosely referring to "spiritualist" but I took his intent to mean a symbol of rejection of religion. The only symbol I would wear is Atheist. All other mystical nonsense can be filed away under "Wrong side of History". But that's me.

Interestingly enough there is historical precedent for this, the pagan Vikings never wore Thor's hammer until after they encountered Christians and saw of them wearing the cross, quite literally they liked the style but did not wish to wear the symbol of another religion, as a result of which they reached into their own mythology and produced pendants of Thor's hammer. You could for example acquire a charm, such as might be found on a charm bracelet, of something which represents science, for example a microscope charm, which you can wear as a pendant, symbolising reason over superstition.

Plenty of them.

As one of us godless heathens, you would have to choose which you prefer.

No god to tell you now.

Buddhism is rife with symbols, especially at the Tibetan end of the spectrum. Wear an OM?

The celts seem to like the tree of life.

Wear a candle for amnesty international?

Heck, your local sport team could do with one more cheer.

On the other side of one of the religions?

It's your choice as to the symbols you use.

The cross is a fine and powerful one. So is the OM.

Empty Set

I have a religious symbol. It's a question mark.

I think the poster simply wanted to know about a symbol which reflects the non-religion person and the atheist 'A" symbol is as good as any. A reasonable question. I bought some "A" pins from the Richard Dawkins website (being on their list and admiring the man greatly) and I wear them on my coat whenever possible. They are not that easy to buy. Check online. Women can wear pendants, as one poster said, but for fellas the options are fewer. People do see it. I was at a social event recently, wearing an Atheist "A" pin, and a Reverend chappie saw it and and engaged with me. It was an interesting conversation. You know, religionists are aware of and in some cases alarmed that non believers are forthright these days, including wearing symbols. They like the good old days when people were sooooo respectful of religions. Welcome to the 21st Century. New approach needed. Look at us here.

I wear the "atheist A" its a nice sterling silver pendant, not big and on a sterling chain.

The plaque

[amazon.com]

I'd go with this. There are also plaques to put on your car.

[etsy.com]