Taken together, these three nights form the basis of the religion.

They are known as "l'organisation", ("the organisation"), in Gabon and "el trabajo", ("the work"), in Equatorial New Guinea

The Ngoze, the ceremony, takes place over three consecutive nights,
Efun, the beginning -birth- ;
Nkeng, the heart -death-;
Meyaya, re-birth.

In certain chapels, the Efun, the first night, is spread over two days: the Efun Begn - the Wednesday evening, when the ceremonies are organised and the musical arc, the "Be", or "Begn", (known as the "instrument that created the world"), is played. On the Thursday, the Efun Ngoma, the Ngoma, the Sitar, is played.

The ritual is replayed each night, with various changes that relate to the varying symbolic elements specific to each night.

Many outsiders find it surprising that a religion that relies on the consumption of a hallucinogenic substance to form the basis of it's initiation rites should have such a formalised structure. And that such attention is placed on meticulous preparatory details.

Most elements of the initiation ritual, the Ngoze, are derived from the rituals of the Mitsogo Bwiti. Indeed, the word "Ngoze" is a Mitsogo word. The main other source of inspiration is Christianity. One effect of the Fang Bwiti's sychretisism, their willingness to absorb elements from diverse religious sources, is that many of these elements, when reproduced in the Bwiti context, appear quite transformed. Aspects of Christian religious belief recover their original meaning and lustre, something lost in the West where the passing centuries have had their effect.

One way in which the Christian influence is apparent is through the significance placed on the number 3. Seen in the 3 Gods of the First Egg, the 3 nights of the ceremony, the 3 Nganga, the 3 Yombo etc.

It's of interest to note that there is no orthodox or standardised form of the Fang Bwiti initiation ritual. And that considerable variance is seen from one chapel to the next. Bwiti is practiced by more than half the Fang people of Gabon and Equatorial New Guinea. And is developing extensively amongst the Pahouine people of Cameroon.
Several distinct branches of Bwiti have developed over the years.

A. Marie, in "la naissance à l'envers", (Born upside down), gives a detailed and comprehensive description of the 3 nights of Ngoze as recorded at the well known chapel, Assumgha Ening:

cf S. Freud "obsessive acts and religious exercises", in the maintenance of an illusion. PUF , 1971, p 81.

and don't forget the Kambo is there to uphold the law...