In 1966, initiated by several servants of God under the auspices of the YPI (Yayasan Penyiaran Injil) and the Madrasah Alkitab Asia Tenggara (MAAT) in Malang, the Holy Word Christian Church was established in Medan. The initial congregation rented a house at Jl.Veteran no.34, Medan, to be used as a church and a space for Sunday school for children. Within 2 years, the congregation experienced rapid growth, and the number of children attending Sunday school also increased.

In light of this situation, in 1968, Rev. Ong Yong Hua (Rev. Yusuf Handojo Ongkowijaya), a minister serving in GKKK at the time, proposed to the church leaders and congregation to purchase their own land for use as both a church and a school, considering the potential of the many children attending Sunday school. He believed that the church’s growth would be more effective if it had a school, allowing the spiritual development of the children from Sunday school to be integrated with their education. This plan was supported by some economically capable members of the congregation. Eventually, both the church leaders and the congregation fully supported the purchase of their own land. Fundraising for the church and school land purchase began, while on the rented house premises at Jl.Veteran 34, the establishment of a kindergarten with two classes commenced.

Pada tahun 1969, atas anugerah Tuhan, GKKK-Medan membeli sebidang tanah dengan luas +/- 3.146 m2 di Jl. Mayang no.10, Medan. Beberapa perbaikan dilakukan di atas tanah tersebut, dan akhirnya di tahun 1969 secara resmi di berdiri bangunan gereja yang dinamai Gereja Kristen Kalam Kudus dan sekolah yang dinamai Sekolah Kristen Kalam Kudus. Pada saat itu, sekolah masih hanya ada TK sebanyak 2 kelas, dan SD sebanyak 3 kelas (kelas 1-3). Barulah pada tahun 1972 Sekolah Kristen Kalam Kudus memiliki kelas yang lengkap di jenjang SD yaitu kelas 1-6.

The subsequent development of Holy Word Christian School was blessed by God. As the years passed, the school expanded to include middle school and high school levels. School facilities were also developed. In 1983, the four-story building on the right side of Jl. Mayang was completed, and a dedication service was led by Pastors Pieter Wongso, Buby Ticoalu, and Timotius Chandra.

In 1996, Kalam Kudus Christian School, located on Jl. Kapten Muslim, began operating on land covering nearly 10,000 m². And in 2011, Holy Word Christian School, located on Jl. Rambung no.9, also started operating on a piece of land covering almost 2,400 m².

Today, Holy Word Christian School – Medan consists of two units. Unit SKKK-1 is located at Jl. Mayang no.10, Medan (covering middle and high school levels), and Jl. Rambung no.9 (covering preschool, kindergarten, and elementary school levels). Unit SKKK-1 is primarily intended for the Global Christian Class (GCC), which is currently operational for preschool, kindergarten, elementary school, and middle school levels. Unit SKKK-2 is situated on Jl. Kapten Muslim, Medan (covering preschool, kindergarten, and elementary school levels), and currently, the educational levels in this unit are classified under the Regular Christian Class (RCC).