There is one God, Ngai (Mugai, Murungu, Mwenenyaga, Muikumbania, Maagu, Githuku), the creator and giver of all things. He has no father, mother, or companion of any kind. His work is done in solitude. He loves or hates people according to their behavior. The creator lives in the sky but has temporary homes on earth, situated on mountains, where he may rest during his visits. Ngai is a distant being and takes little interest in individuals in their daily walks of life. Yet at the crises of their lives he is invariably called upon. At the birth, initiation, marriage, and death of every Kikuyu, communication is established on his behalf with Ngai. Ngai, not visible to mortal eyes, manifests himself in various ways: the sun, the moon, the stars, rain, rainbow, lightning, and thunder are looked upon as manifestations of his powers. Through these signs, he expresses his love or hatred.
In prayers and sacrifices, Ngai is addressed by the Kikuyu as Mwene-Nyaga, possessor of brightness. This name is associated with Kere-Nyaga, Mount Kenya, a phrase that refers to that which possesses brightness. The mountain of brightness is believed to be Ngai's official resting place, and when people pray they turn toward Kere-Nyaga. The Kikuyu are descendants of an old man and his wife, who came to the present country from the other side of the great mountain of Kenya. While they were on the slopes of the mountain, they were on the point of starvation, and the old man went up the summit to see Ngai, who dwells there. Ngai on that occasion gave him sheep and goats, and from that gift all the flocks of today are descended. Ngai told the old man that his descendants should occupy the present Kikuyu country, and that they should live by tillage; that the Masai should hold the plains, and should have flocks and herds; that the portion of the Dorobo should be the wild game of the wilderness and nothing else.
In the beginning, all the people of the earth were immortal. Long ago, the great god Ngai sent the chameleon to assure the people of the earth that they would never die. But when the chameleon left, Ngai changed his mind. He summoned a bird, and told him to go quickly and proclaim to all the people of the earth that they shall die, and never return. The bird flew swiftly and arrived on earth to hear the chameleon hesitantly stammering the message. Without hesitation, the bird proclaimed the divine message: “The great god has said that all men shall die and shall never return.” The chameleon had stammered too long and had failed to announce its message. That is why all men must die.