I enjoy saying hello to Sikhs when they come to the Kotel. They are almost always friendly, quick to smile. They are originally from the Punjab in northern India. Although you rarely hear about them, there are approximately twice as many Sikhs in the world as there are Jews.
Their religion is monotheistic. They believe that G-d is one, immortal, and everywhere. Their major religious effort is to try to develop a personal relationship with G-d, mostly through meditation.
The men wear turbans to cover their lifelong uncut hair. Recently, a Sikh told me that as a teen he wanted to cut his hair but his mother reminded him of what happened to Samson when he cut his hair, so he did not cut it. Samson was a nazir [i] from birth which means that he never cut his hair. When his hair was cut he lost his amazing strength and was captured and enslaved by the Philistines.
Sikhs do not seek converts and they appear to be friendly with all other religions. I like them.
[i] A Jew who vowed to abstain from certain things for a period of time