In Efik mythology, Abassi is considered to be the Supreme Creator (God). His wife, Atai, is known as the mediator. It is believed that Atai convinced Abassi to allow two humans (one man and one woman), also known as their children, to live on Earth, but forbade them to work or reproduce. The children were required to return to heaven with Abassi whenever he rang the dinner bell. These rules were established so that the Efik people would not surpass Abassi in wisdom or strength. Eventually the children disobeyed and Abassi killed them both. Abassi and Atai were disgusted and gave the humans two gifts, chaos and death.
It was originally believed that Abassi and Atai live in the Sun. Abassi is the spirit of health. The tribesmen would often chant aloud to the sun in hopes that Abassi would hear their cries and heal them. It was believed that Abassi gave certain tribesmen the ability to heal the sick through necromancy. Whenever someone in the tribe was ill, the chief would summon the witchdoctor. Within a healing ceremony, the tribesmen would start a fire. All the people of the tribe were required to gather around as they sang songs of worship to Abassi.
It was also believed that twins were a disgrace to Abassi. It was thought to be evil for a woman to give birth to twins; the woman would be burnt alive and the twins were taken and left for dead in the desert.
The Reverend Hope Masterton Waddell came among the Efik people on 10 April 1846. The Efik people specifically requested for the evangelization of their kingdom in writing and the letters are dated 1 December 1842 and 4 December 1842 from King Eyo Honesty II and King Eyamba V respectively. Mary Mitchell Slessor came to Calabar in 1876. The Atai referred to as the wife of Abassi was the third Edidem of the Efik people. He was the king who led the Efik people out of the country of the Aros into Uruan country.
- Benge, Geoff (28 July 1999). Mary Slessor: Forward into Calabar (Christian Heroes: Then & Now). YWAM Publishing. p. 203.
- Jackson, Dave (1 May 1994). Trial by Poison: Mary Slessor (Trailblazer Books #12. Bethany House. p. 144.
- Basil Miller (June 1985). Mary Slessor (Women Of Faith Series). Bethany House Publishers. p. 144.
- Livingstone, W.P. Mary Slessor of Calabar.