One of Asia’s largest churches by capacity, the Sumi Baptist Church stands at an elevation of 1,865 metres on a hilltop at the centre of Zunheboto district in Nagaland, India. Dating to the 1940s, the church was rebuilt more recently to accommodate a larger congregation, with the new building opened to the public in 2018. Designed by Naga architect Honoholi K Chishi-Zhimomi, the church stands as a visual marker of the history of Christianity in Nagaland, particularly the conversion of the Sumi Naga people in the twentieth century.  

One of the Adivasi peoples of the Naga Hills on the India–Myanmar frontier, the Sumi are a major ethnic group in present-day Nagaland. Beginning with the efforts of American missionaries, a large majority of them converted from their ancestral nature worship traditions to Christianity during the twentieth century. American Baptist missionaries had arrived in northeastern India in 1835 with the aim of converting people in this region as well as parts of Burma (now Myanmar) and China. Although less successful in the latter countries, by the 1880s they had set up missions in areas populated by the Ao, Lotha and Angami Naga groups, in present-day Nagaland. It was only in the early twentieth century that the missionary efforts reached the Sumi Naga in the remote interiors of the Naga Hills. The baptism of the gaonburas, or the village headmen, of Ighanumi village in 1904 marked the advent of Christianity among the Sumi. Despite significant conflict between new converts and followers of the traditional faith, conversion to Christianity took place on a large scale among the Sumi during the 1920s and 1930s. In what was considered a major success for the American Baptists, the conversion was largely facilitated by the Sumi people themselves, particularly driven by interest from the economically vulnerable for whom Christianity promised greater social access. They were able to spread the gospel across poorly connected villages and with little missionary intervention or funds. In 1929, the Sumi Baptist Church Association was founded, and in 1936, the first Sumi missionary centre was built in Aizuto. 

Missionaries such as JE Tanquist attempted to unite the Baptist activities among the many Naga groups spread across several present-day states of Northeast India. Remaining relatively local, however, what he founded as the Naga Hills Baptist Church Advisory Council (NHBCAC) in 1935 underwent various changes, shifting its focus between geographical area and the conglomeration of ethnic groups, until, with Nagaland’s statehood in 1958, it was renamed the Nagaland Baptist Church Council (NBCC). In the late 1950s, the NBCC grew in prominence after the Indian government expelled foreign missionaries from the country, particularly from areas occupied by Naga groups. It currently serves as a united platform for Naga Baptists and churches to address their concerns and carry out missionary work. 

Affiliated with NBCC, the Sumi Baptist Church was founded at Zunheboto in the 1940s, with the original building thought to date to 1945. Little further information is available on the structure except that it accommodated three thousand people. A new building was commissioned in 2004 to provide a space for the growing congregation and enable Sumi Christians from across the district to gather in one place. The project was given to Dimapur-based firm Akitektura, with architect Honoholi K Chishi-Zhimomi leading the design. The construction of the building began in 2007 and was completed ten years later, in 2017. While half of the funding was provided by the church, nearly half was acquired from the congregation, with each member contributing according to their economic ability. 

The strategic location of the church at the crest of a hill makes it visible from about twenty villages across the district. The earthquake-prone region coupled with the altitude of the church, however, posed challenges to construction and safety, which were addressed through careful engineering. Built in an ovoid, or egg-shaped, plan, the structure incorporates Gothic, Classical and Modern elements. It can seat 8,500 visitors in its 60-metre length and 43-metre width. Equivalent to the height of an eight- or nine-storeyed building, it stands approximately 50 metres tall, its verticality accentuated by several narrow, rounded tower buttresses running up the full height of the facade and capped with conical pinnacles, a large number of which line the top of the church. Three cylindrical steeples extend upwards from the roof, the highest one topped with a spire and cross. The entirely white facade of the building is offset by the blue paint of the spire, steeple tops and the broad pyramidal roof that covers almost the full width of the church. It is also lined with Gothic-style pointed arch glass windows in varying sizes — smaller along the middle and larger at the ground-floor and the higher levels. The church houses a 500-kilogram brass bell imported from Poland, placed to the right of the church entrance, whose sound is said to have a reach of 1.5 kilometres.

The main sanctuary inside the church comprises a central stage surrounded by tiered seating. Within the stage is a hidden pool that is used for baptisms. The church contains twenty-six additional rooms, including a separate chapel with three hundred seats; three conference halls; offices; dressing rooms predominantly used by brides and grooms getting married at the church; a playroom for children; and a sick room. A cafeteria and library are located below-ground, serving as spaces for the community to come together after worship. The church is also equipped with two elevators.

While having discontinued many of their ancestral rituals in favour of Christian practices, the Sumi retain certain ceremonies rooted in nature worship, incorporating them into church worship. For instance, they continue to present the first harvest of the season and the first offspring of their cattle or fowl to the church as offerings. In 2019, the Tuluni festival — an annual Sumi celebration of the first harvest — was held at the Sumi Baptist Church. 

At the time of writing, the Sumi Baptist Church serves as the district headquarters of the Sumi Baptists and is one of the primary religious institutions in Nagaland.