Bah Rahu Hassan was born to a Sengoi couple, Bah Hassan and Wah Itam, in Ulu Geruntum, a village nestled in the mountains of the Main Range of Peninsular Malaysia. The Sengoi, also known as Senoi, are the largest group of native peoples in Peninsular Malaysia.^[1] 

Bah Hassan and Wah Itam had 12 children but only six survived into adulthood due to the high infant mortality rate among indigenous people. Bah Rahu became the first Orang Asli pastor in Peninsular Malaysia while his siblings Bah Serap and Bah Telpus later became full-time workers under the Sengoi Mission.

Bah Hassan, the headman of Ulu Geruntum, had heard about education for children from missionaries working among the indigenous people along the Tapah to Cameron Highlands road.^[2] So, one day in 1953, his son Bah Rahu walked out of the jungle with six other children and took a bus to Kampar, about 12 miles from Gopeng, to the home of an American missionary couple, Lionel and Marion Muthiah. The Muthiahs were missionary teachers at the Methodist Secondary School (popularly known as Anglo-Chinese School) and Lionel also served as lay pastor of the Wesley Methodist Church in Kampar. Lionel arranged for them to be enrolled at the Methodist Afternoon School as they were past the age to join regular government schools.^[3]

The indigenous people at nearby Batu Berangkai, a village at the foothills of the mountains, agreed to house the children so they could walk to school from there. Lionel got donations from the church and community leaders and provided food for the children to cook. 

Bah Rahu almost had to drop out when he was in Form Three because his father could not afford the school fees.^[4] The Methodist Mission later helped to bring Bah Rahu to the Methodist English School in Bentong in Pahang which had hostel facilities. There, he was mentored by Ted Miles, the school principal. When Miles was transferred to Kuantan, the state capital, Bah Rahu went with him and completed his Cambridge School Certificate there in l968.

Bah Rahu was baptised in 1962^[5] and his witness as a Christian led his parents to become followers of Jesus Christ. In 1964, Bah Hassan, his wife Wah Itam and 33 villagers were baptised. Eventually, the whole village of Ulu Geruntum became Christian.

On the way back to his village after completing his Senior Cambridge, Bah Rahu stopped to rest at the Gombak Hospital in Selangor which served indigenous people. A Peace Corp^[6] doctor there asked Bah Rahu to consider working at the hospital. But during his two-night stay there, Bah Rahu heard a voice telling him, “Go back and help your people.” On both nights, he asked, “Help to do what?” The voice repeated: “Help your own people.” The next day, Bah Rahu packed his belongings to return to Ulu Geruntum.

Lionel Muthiah was instrumental in getting Bah Rahu involved in mission work among the Sengoi people, in particular the education of Sengoi children. As the work among the Sengoi grew, the Methodist Church Board of Mission saw the need for more field workers. Bah Rahu was sent for a Bible translation course in Madras, India by the Bible Society in 1969, after which he was enrolled in a theology course at the Trinity Theological College in Singapore.

But he found the course too academic and left after a few months. He returned to Malaysia and got a job as a laboratory technician at the Gombak Hospital where he had first heard the voice calling him to go back and help his people. Part of his job involved accompanying his superiors on helicopter trips to treat indigenous people in the jungle, many of whom were dying from malaria and other diseases. 

While at Gombak Hospital, Bah Rahu had received two letters from the leaders of the Methodist Board of Mission. He kept the unopened letters next to his Bible. When he fell ill and his whole body was in such great pain that he had to be hospitalised, his thoughts turned to the two letters and he finally read them. They offered Bah Rahu a position in the Sengoi Mission. But it meant he would have to leave his job at the hospital. 

He then prayed that God would heal him if He wanted him to return to Kampar to serve. The next day, he resigned and returned to Ulu Geruntum. There, the pain in his body gradually disappeared and he joined the Sengoi Mission team to teach and help in the training of field workers, working alongside Reverend Jerry Rabbu, Reverend Andrew Mengka, Reverend Samuel Chong, Samuel Liew and Reverend Herman Shastri.

In 1974, he was sent for theological education at the Bible School in Medan, Indonesia where he graduated with a degree in theology. He worked with the Board of Mission of the Singapore Malaysia Annual Conference (SMAC) of the Methodist Church in Malaysia. In 1976, the SMAC split into two Conferences – the Trinity Annual Conference (TRAC) Singapore and the Trinity Annual Conference (TRAC) Malaysia. 

TRAC Malaysia created the Board on Sengoi Mission with the objective of forming a native church Conference within the Methodist Church in Malaysia. The board was given the task of assisting the native churches to grow strong enough to form a Sengoi Provisional Annual Conference one day. The Sengoi Workers Training Centre (SWTC) was set up in 1980 in the now defunct Methodist School in Kampar to bring about change and help uplift the Sengoi community in Peninsular Malaysia, with Reverend Shastri and Bah Rahu playing key roles. 

To further equip him, Bah Rahu was sent to All Nations Christian College in the United Kingdom for further studies from 1984 to 1987. In 1986, he was  ordained as an Elder of the Trinity Annual Conference.

His people were animistic and Bah Rahu wanted them to know the truth about God, to be set free from all fear and superstition and to trust in the living God instead of consulting bomohs (witch doctors). He wanted the Sengoi to be educated so they could escape ignorance and poverty. 

Wong Young Soon, former executive director of Malaysian Care and a mentee of Bah Rahu, recalls: “He once said, ‘I want to see my people develop holistically. The gospel makes the whole self of a person – someone who knows who he or she is. To think, what does it mean to be an Orang Asli? What does it mean to be a Christian? Knowing their identity, knowing how to live in life and then to live out the Bible.’”^[7]

In 1990, Bah Rahu became the principal of the Sengoi Workers Training Centre, a position he held until 2005. He was also the District Superintendent of the Sengoi Mission Conference, which had a membership of more than 5,000 members, 16 pastors and 36 churches spread out among the villages in the mountains of the Main Range.

During this period of growth of the Sengoi Mission Conference, Bah Rahu met with a hit-and-run accident while travelling on his motorcycle from Ulu Geruntum to the Sengoi Workers Training Centre in Kampar. He was sent to the Ipoh General Hospital and was subsequently transferred to a private hospital where he received treatment from a Christian orthopedic doctor for a fractured leg and collar bone. Although his bones healed, it took 10 months for him to fully recover and he walked with a slight limp. Despite that, he went on serving faithfully, and the Perak Methodist churches bought him a four-wheel drive vehicle which made travelling safer for him. On his retirement in 2005, the Sengoi Mission Conference had 7,203 members, 24 pastors and 74 churches.

On the morning of January 10, 2011 while tapping rubber in his plot of land at  Ulu Geruntum, he felt sudden chest pains. He passed away in the car as his family was sending him to the Ipoh General Hospital. Leaders of the Methodist churches turned up in full force to attend his funeral the next day. Bah Rahu was buried in the village cemetery in Ulu Geruntum. He is survived by his wife Wah Nantin, a Bible translator with Wycliffe, and his daughter Wah Deja.^[8]

In describing Bah Rahu, Reverend T. Jeyakumar, Bishop of the Methodist Church in Malaysia, borrowed from the words of John Wesley. “Bah Rahu was immovable in the things of God.” “His life, his ministry, his leadership, his courage, and his soft-spoken demeanour are to be remembered and emulated. The Methodist Church in Malaysia and the Persidangan Misi Sengoi Methodist (PMSM) owe so much to him for his arduous labor of love which he faithfully carried out until the Lord called him home.”^[9]