Before Olooseos parish was started, a p.c.e.a church at Olooseos village started in 1952. The then Rev Ishmael Wango moderator of Mbagathi Kirk Session together with Christians from Ngong assisted in putting up a structure that was used as church and classroom by then.          

When the state of emergency was declared members of Olooseos village were moved to Kiserian Village. The structure was dismantled and rebuild at Enoomatasiani in the same year.

In 1965 during the reign of chief Moses Murero Ole Moiko worship service started under a tree near his home at Olooseos again. Neighbours joined his family for Sunday services.

Later, Rev. Moses K. Waweru moderator of Ngong Parish invited students of St. Paul theological college and their lecturer Rev. Swailen Sidhon to spread the gospel at Olooseos area. Some of the students included Samuel Ntiamput Ole Pulei and Timothy Murere Njoya among other.

Rev. Moses Waweru influenced the P.C.E.A headquarters to send missionaries at Olooseos in 1967. Lowrie Anderson and his wife were sent by the headquarter area to start missionary work at Olooseso.

The first structure made of timber and iron sheet was erected in the same year. The building was also used as a nursery school. The first deacon was Samuel K. Nakeel.

The missionary work was bearing fruit and P.C.E.A Olepolos, P.C.E.A Olooshoibor and other churches were started in 1970.

In October 1971 Rev. Samuel N. Pulei was posted to Olooseos to start Olooseos outreach. He replaced Dr. Lownie Anderson who was retiring and going back to America.

The missionary work became more rambat involving more young men and women believers. Over 40 churches were established in Maasai land. The churches spread in areas which include Oloitaktok, Kajiado Magadi and Ewuaso.