The traditional ancient religion of Umuomaku is Odinani, otherwise known as Hedonism. The people of Umuomaku believe in the supreme God who is referred to as Chukwu (the Great Spirit). Chukwu was the creation of the whole pantheon of Alusi spirits to whom he delegated the power to control various aspects of nature and the activities of men. Chukwu was believed to be the creator of heaven and earth and the source of human life. The commonest way of approaching Chukwu in Umuomaku was igo ofo (incantations or traditional religious worship).
Igo Ofo is believed to be a practice that strengthens not only the relationship between man and his Chukwu, but also between man and his fellow men.
The people communicated with Chukwu because they believed Chukwu listened to them, accepted and answered their prayers. The traditional religion recognized the existence of many Gods and condemned all misconduct such as lies, stealing, fornication, arson, indecent act, injustice, rape and killing of a human being. Anybody found guilty of stealing yams in the farm, killing or murder is severely punished.
Next to Chukwu is Arusi, sacrifices were made to Chukwu through the Arusi, oracle and ancestors. Arusi are minor eities that are worshipped and served in Umuomaku. These deities include Awuwo, Uhejioku (god of yam crops), Isigwu, Okwara, Ugaezi, Adaidike and Ekure.
Awuwo deity was established and worshipped by Umueze kindred of Umunambu village in Umuomaku (formerly known as Umuawuwo). The feast is celebrated in the month of September to mark the end of the farming season. It is an annual event. During this festivity, bread fruit popularly known as 'ukwa' is cooked and served. This event lasts for three days.
Uhejioku festival is celebrated to mark the beginning of harvest period in August or September of every year and it lasts for two days. Uhejioku deity originated from Umuoka kindred in Umunambu village. This kindred is the oldest in Umuomaku, this gave them the entitlement of the chief host of yam, the king of all crops. The deity is seen as the god of yam crop.
Isigwu deity is usually performed in the 11th month of the year to mark the commencement of dry season by Nambu, the first son of Omaku which is today known as Umunabu village. During this feast, hunters from within and outside the community usually gather for a hunting expedition and all the bush meats caught are brought to the chief priest as a mark of honour. The hunting lasts for just a day while the feast last for eight days. Food and drinks are served on throughout the duration of the feast. Usually, masquarades perform at Ama Onyeneme village square on the third day.
Okwara deity starts in the 12th month of the year to mark the period. Okpobe village is the chief host of this festival. The duration of this feast is usually eight days.
Ugaezi deity feast comes after Okwara and it is usually celebrated in the thirteenth lunar month to mark the end of dry season and the beginning of the planting season.
Adai deity festival marks the end of resting period and the beginning of planting season. The people of Umuezemarakwa kindred in Umungada village are the chief celebrants