The Marapu religion (also known as Marafu in Sumba) is a form of ancestral religion that is practiced mainly in the island of Sumba in Indonesia. Marapu is also practiced in many more remote areas of Sumba and Flores. Both the Christians and Muslims on these islands tend to combine their faiths with Marapu. Since Marapu, like Kaharingan of the Dayaks, is not an official religion of Indonesia, and all Indonesian citizens are required to identify as of one of a member of the sanctioned religions by law, members have chosen either Christianity or Islam to self identify.
They believe in temporary life in the world and eternal life in the Doomsday, the world of spirits in Marapu heaven — Prai Marapu. The word Marapu means: Firstly, the occupants of the eternal heaven, who lead a similar existence to men. They live in couples and one of these couples is the ancestor of the Sumbanese. Secondly, the spirits of Sumbanese ancestors in Prai Marupu. Thirdly, the spirits of their relatives. Fourthly, all spirits dwelling the universe. Marapu has mysterious and magical authority over human life.
According to Marapu beliefs, any spirit consists of two elements: Ndewa and Hamanangu. Marapu teachings concern the balance of universal life through which happiness can be gained. This balance is symbolized by the Great Mother (Ina Kalada) and the Great Father (Ama Kalada) who live in the universe and take the forms of the moon and the sun. In mythology, they are husband and wife who gave birth to the ancestors of the Sumbanese.
To honor Marapu, the Sumbanese put effigies, called Marapu statues, on stone altars where they lay their offerings in the forms of Sirih Pinang (a dish containing betel leaves, nuts and lime) and sacrificial cattle. The statues of Marapu are made of wood in the shape of human faces. These images are usually placed in the yard of their houses or inside the traditional houses.
A further manifestation of devotion to Merapu and the ancestors is reflected in the continuing construction in parts of East Sumba of impressive stone burial monuments, vestiges of one of the last surviving megalithic cultures on the planet. In many cases individuals will put their families into debts extending into future generations in order to build these tomb stones in the traditional manner.