GKI was established in continuity with the Indonesian Christian Church in West Java, Central Java and East Java. These three denominations were originally independent, each arising from separate missionary initiatives conducted by local and foreign missionaries. The first of these denominations to be established, later coming to be known as the Indonesian Christian Church East Java, was incorporated on 22 February 1934. Six years later, and coming to be known as the Indonesian Christian Church West Java, the second denomination was incorporated on 24 March 1940. Finally, on 8 August 1945, the Indonesian Christian Churches Central Java was incorporated. Since 27 March 1962, the three denominations have been united as the Indonesian Christian Church, with the overall governing responsibility maintained by the General Synod, which aims to co-ordinate united efforts towards common goals. Both GKI West Java and GKI East Java were originally affiliated with the Dutch Hervormd mission, whereas GKI Central Java was affiliated with the Dutch Gereformeerd mission. Additionally, GKI West Java originally included a number of congregations operating as a distinct presbytery, which was affiliated with local and foreign Chinese Evangelical missions. Despite the differences in liturgy and church government between the various congregations and denominations, all the congregation from the three previous GKIs, without exception, consented to the merger at the time GKI united.
Organization
GKI's organization consists of the congregation, presbytery, regional synod and Synod. Each organisation respectively was led by the congregation council, the presbytery council, the regional synod council and the synod council. As the Synod consists of regional synods, regional synod consists of presbyteries, presbytery consists of congregations, so synod council consists of all regional synod councils, regional synod council consists of all presbytery councils and presbytery councils consists of all congregational councils. In short, synod councils consists of all GKI councils which are composed of elders and ministers. Church government in the congregation was run by an executive congregation council, the presbytery assemblies was run by an executive presbytery council, the regional synod was run by executive regional synod council and the synod was run by executive synod council. This kind of organisation was acknowledged as the presbyterial-Synodal system. What was unique of GKI Presbyterial-Synodal is that, each form of GKI church organisation has its own council as servant-leaders, not a mere executive board.
Assembly
The most authoritative forum to make decision in each form of the church organisation is the assembly. The assembly is respective assembly of council in its own scope. GKI hierarchy is made such that the larger assemblies, i.e. consisting of more little assemblies has more authority. For example, the assembly of the congregational council has to submit to the assembly of presbytery council, the assembly of presbytery council has to submit to the assembly of regional synod council and the assembly of regional synod council has to submit to the assembly of synod council.
Regional Synods
There are three regional synod in GKI: Regional Synod in East Java, Regional Synod in West Java and Regional Synod in Central Java.
Statistics
The church has almost 180,000 members in 200 parishes and 114 house fellowships in 2004. The church had 220 000 members in 217 congregations in 2012.
Church functions in GKI are ministers and elders. GKI deliberately chooses fewer church functions. Since Elder is a function which GKI believed as being permanent function since the Old Testament to the New Testament. Whereas minister is an inherited function from the New Testament church. However, there are a few GKI congregations keeping the deacon function in their fidelity to old Calvinism.
Liturgy
GKI Liturgy is adapting and referring to the Lima Document and BEM Document of the WCC. The Word of God was ministered by adapting Lectionary. GKI affirms two sacraments, i.e., baptism and communion.
Decision Making
Decision making in each meeting and assembly is undertaken by means of the conciliation method which is parallel to the consensus method.
GKI values its theological heritage which originates from Pietism, Calvinism and Methodism, but prominently classified as mainline Protestant. GKI is doing theology in the context of a church living in the midst of Muslim community. GKI deliberately discontinued its ethnic bond, i.e., to be a multi-ethnic national church in 1958. The church affirms the Apostles Creed, Nicene Creed, Athanasian Creed and the Heidelberg Catechism.
