The purposes of this study were (1) to study the belief in deity in Theravāda Buddhism, (2) to study the principle of relation between man and deity in Theravāda Buddhism, and (3) to study the benefits and value of relation between man and deity in Theravāda Buddhism.

                        A result of this research was found that Tipitaka mentioned the concept of ideas in Vinaya Pitaka, Suttanta Pitaka, and Abhidhamma Pitaka. The Suttanta Pitaka mentioned many deities. It collected all stories of the deity called ‘Devatā Saṁyutta’. Buddhism accepted the fact that the deity was found and it was a special being in itself, i.e. a supernatural body, beautiful ray, long life, a member of the heaven, attraction to five desired materials, supernatural absorption and power, etc. The deity came from a human being who had pure action of a body, speech, and mind. This human being had to go to the heaven in the future. Buddhism represented the principles to make a human being a deity in three ways of making merit, ten ways of making merit, fourfold achievement, sevenfold Vattabot, and Devadhamma. These principles were very useful for people because they gave them a good support, a possible hope, and they helped them to live with carefulness and to go to the heaven after death.

                        The deity’s role was found that the deity had the positive roles such as giving a good service to the meditators, and meeting the Buddha for listening to his sermon or for asking the problems. The deity also had the negative roles such as being jealous, and disturbing and controlling the anxious person in the immoral ways. Human beings played their role on the deity in four ways: (1) Devatāpli—dedication of merit to the deity, (2) Devatānussati—consciousness of morality or qualities like faith and morality to make a human being a deity, (3) Mettā—the presentation of good wish towards that deity, and (4) invitation of the deity such as invitation of the deity to listen to the sermons as seen in the Buddhist ceremony to invite the deity in the organized ceremony before the monks’ chanting.

                        The relation between man and the deity was found in the fact that most people were associated with the deity in the real practice because they wished to be protected by the powerful deity. As a result, the general deity was a powerful being. The story of the deity was secret, supernatural, inconclusive, and indemonstrable with cause and effect. People who did not believe in it could not prove and present it in the public. The proof of that thing caused many damages in a person and societies. Moreover, this action caused the damage of limes and business because it was timeless and required a proper time to prove whether it was true or not. Therefore, the best benefit of life was to know things clearly as they really were, and to understand the truth of the component things without becoming a slave of materials and life. People had mind free from the attack of attraction, defilement, suffering, and then, they would met the supreme happiness with perfectly pure, peaceful, delighted mind, generally called Vimutti and Nibbāna.