The last stage of initial formation is done while the student undertakes theological studies. Immediately after profession, a candidate is enrolled at Tangaza College in Kenya for a four year theology course. Tangaza is a constituent College of the Catholic University of Eastern Africa. It is situated in Nairobi and is run by the Board of directors that consists of Major superiors of different congregations.

The Passionist Theology house is called Kisima and is situated about three kilometres from Tangaza College. Kisima is an international house of studies comprising of students from Eastern and Southern Africa where the Passionists are mostly found. An exceptional case is with Congo where the Congolese Passionists do the whole formation within their country.

Like the pre-novitiate stage, this stage of theology concentrates more on studies. However, weekends and other select days are set for manual work, sport and other activities of the house. Moreover, special attention is given to pastoral activities. This is to help students prepare for the future ministries. Therefore, special areas are identified and students are allocated in those areas for pastoral experience. This is done once a week but on different days. Furthermore, during the long school holidays, students are given an opportunity to do pastoral work for at least a month from their respective places. It is also during these holidays that students renew their vows yearly. After a successful completion of the four year program, a student is ready to make final vows of evangelical counsels.

NB: The above description is very particular to candidates for priesthood. The brother candidates take a slightly different route. After novitiate, brother candidates are taken to different schools depending on what they wish to study and unless the congregation considers it fitting.