Bhenji,
I have often in my life come across the Guru's and their teachings in the most unlikeliest places, years ago, 20 to be precise, when I was younger and much more stupid than I am now,I went to a faith healer, who attempted to retune my chakras, she played a tape of chanting, which basically consisted of the names of all ten gurus being chanted to harp music.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=36337
I think, on the plus side, we should be honored that someone agrees with our teachings so much, that they are happy to take them on board, but on the negative side, if the teachings are being distorted they may lead some people onto a path that is not sikhi.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=36337
Having said that, I am convinced that the Sri Guru Granth Sahib Ji contains the template on how to connect with the creator, I am not convinced that all other religions place such a huge priority on your conduct on the earth for the sake of learning and goodness , as opposed to say, ambrosia, nectar and heaven, but the ones that do push forward heaven and hell as a concept of life on earth, would, I imagine have similar thoughts as to us.