I have gone through the other answers  and I am not going to touch those points.

Hinduism believes in god, its true but while writing all scriptures of the Hinduism like Vedas, Purana, Srimadbhagavatam, Srimadbhagawatgita etc by the sage named Krishna Dwaipayana Vyasa and his disciples like Pailya, jaimini and others divided man into four castes like -Brahmans, Kshatriya, Baisya and Sudra. He also divided the works to be performed by these castes. Brahmans are to worship, Kshatriya  to rule, Baishyas to do business and Sudras to cultivate and look after welfare of other three branches. The Brahmans lost their sanctity and began to exploit other in the name of religious matter like the monks in Christianity. Condition of other branches deteriorated and suffered a lot.

Buddha, who was the prince of an Indian King named Sudhodhan of Kapilavastu, saw this and felt much for the poor condition of people. He also utterly realised how people became sad at the death of their near and dear one. He found out that it was because of ignorance. So he went out inquest of real knowledge leaving behind his legacy and his wife.

He found that God is the mass of energy and it is difficult for all to realize without knowledge. So he taught-a) Dharmam saranam Gaschami b)Budham(knowledge) saranam Gaschami c) Sangham saranam Gaschami. He appealed people to come unto him, acquire real knowledge without which people suffer from weal and woe and to acquire them together in unity. He taught people how to get 'Nirban' to be free from all anxieties by acquiring knowledge that this phenomenal world is only a perception nor real. Then would aspire nothing and aspirations are the real cause of our sadness.