Starting from the unity of God, Nanak and his successors rejected the idols and incarnations of the Hindus, and on the ground of the equality of all men rejected also the system of caste.
Outwardly they are Mussulmans of the Shiah branch, but most of them show little veneration for either Prophet or Koran, and the religion of some of them seems to be a mixture of Ali-Illahism involving a belief in successive incarnations combined with mysterious, ancient, heathen rites.
Their babies are incarnations of spirits which quitted a bush or rock passed by the mothers at the moment of conception.
The historic Buddha - the man Gautamais taught as only one of a limitless series of incarnations or (better) appearances.
But despite the artificial character of the Trimurti, it has retained to this day at least its theoretical validity in orthodox Hinduism, whilst it has also undoubtedly exercised considerable influence in shaping sectarian belief, in promoting feelings of toleration towards the claims of rival deities; and in a tendency towards identifying divine figures newly sprung into popular favour with one or other of the principal deities, and thus helping to bring into vogue that notion of avatars, or periodical descents or incarnations of the deity, which has become so prominent a feature of the later sectarian belief.