Ragnar
<--- Pic is not me
Still not origin.
Do you even know any Indian people? More specifically, Sikh's? If you do, ask them.
Wikipedia is sadly lacking on the origin.
I didn't know much of anything about Sikhism before today except they were separate from Hindus and Muslims and were particularly decent and peaceful.
I read the link I posted from wiki and if it's accurate at least in the broad strokes then Sikh's worship one universal god, believe in reincarnation and most impressively have a very (very very) long history of tolerance toward religious minorities and rights.
That's wiki so, that links basically an incomplete Cliff's Notes.
Only known a small handful on Indian people in my life and they were Hindu, Christian or atheist like myself.