Bellona and Rennell were among the last Polynesian islands to convert to Christianity. Their almost complete isolation before and during the World War II prevented the population from acquiring extensive knowledge about Christian doctrines, but this isolation made it possible for an anthropologist to acquire a detailed picture of a pre-Christian Polynesian religion. The islanders believed that the world was inhabited by an impressive hierarchy of gods, deities and worshipped ancestors classified as sky gods, who were associated with the universe and with the non-socialized nature surrounding human beings.
District deities comprised a lower level of supernatural beings, whose existence was organised as that of human beings and who protected society in its present form. Ancestors acted as messengers between the world of humans and that of gods and, the deities were taking goods, wealth, and new children to the island societies. Almost no act was carried out without communication with the super naturals. The most important pre-Christian ceremonies were the harvest rituals performed in cycles within the patrilineal descent groups, each lasting two or more weeks and taking place either in the temples or homesteads Uncooked tubers were presented to the sky-gods, and cooked food to the district deities and ancestors. The food then was distributed among the participants.

In October 1938, a meeting was held in the homestead, ’Niupani, at the lake of East Rennell. A series of rites were conducted both to the Christian god and to the old deities. After a short period of social and ideological chaos the Christian faith became dominant on Rennell. Shortly after, a group of Rennellese went to Bellona to announce the dismissal of the old deities and the two islands were proclaimed Christian. The old deities were chased away to their abodes at the eastern horizon. The two stone images of the superior godly couple were crushed; sacred buildings and areas were destroyed and uprooted. A few years after the end of World War II, foreign missionaries ordered the islanders to build churches and establish villages around them instead of the houses along the main trail.

The first Adventist church was founded on Rennell in Hutuna at the lake. Later, in Tahamatangi and Tegano the South Seas Evangelical Mission (an Australian sect) built two houses at the lake. On Bellona the Adventists built a church in Ngongona and at the same time SSE Mission built one in Kapata. Over the years the missions founded new churches with surrounding villages and during the 1970s, 1980s, and 1990s, a few families converted to Baptism, Baha’i, the Anglican Church, and the fundamentalist Adventist Church Concerned Bretheren (CB). In all, twenty-eight local religious communities were established on the two islands at the turn of the millennium.

In the pre-Christian religion all adult men had religious roles. Three formal types were distinguished: priests, second priest chiefs and assistants to priests. An informal role was that of a medium who, occasionally, was possessed by a district deity or an ancestor, and who, in a twisted voice, spoke through him. The first two Christian denominations established, were the South Sea Evangelical Mission (later South Sea Evangelical Church) and Seventh Day Adventists. Both still adhere to the beliefs of the first foreign missionaries arriving in the Solomon Islands. However, their doctrines are less philosophical than those of either pre-Christian belief of their islands or of Western theology.

When asked about the differences between their beliefs both sects claim that the only difference is the time of worship: Saturday versus Sunday. However, the strict food taboos of the SDA and the payments of a tithe of 5 to 30 percent of one’s earnings differ from the practices of the SSEC, which collects cash during church services. The Seventh Day Adventists do not believe in death. They believe death and resurrection will take place after the second coming of Christ and is an event eagerly wished for. They believe (like the SSEC) that dead people sleep until the second coming of Christ is fulfilled and then, but not till then, the rewards and punishments will be measured up.

In the pre-Christian era death and afterlife involved a long series of rituals and extended mourning. The beliefs were that dead individuals left the islands, went to dance on the reef and were taken to the abodes of the gods under the horizon to live there and grow old. Then some were “pulled” and others annihilated. Those “pulled” were rejuvenated and their old skin removed; they remained with the gods and were worshipped as ancestors by the living people. Those low-status individuals (men and women) about to be annihilated were to go and stand on a perch and then erased on a rough stone in the darkness and forgotten.