The Guru

But a Guru need not always be in human form. First a person thinks he is an inferior and that there is a superior, all-knowing and all-powerful God who controls his own and the world’s destiny, and worships him or does bhakti. When he reaches a certain stage and becomes fit for enlightenment, the same God whom he was worshipping comes as Guru and leads him on. That Guru comes only to tell him. “The God is within yourself. Dive within and realise.” God, Guru, and the Self are the same.”
[Ramana Maharshi]