He was born on 20 July, 1966, in Panyiich, a village near Ganyliel. His parents were not baptised. He grew up like any other Nuer boy. At the age of thirteen he was initiated. Six lines were cut on his forehead as a sign of manhood.

Biel was a teenager full of life and wanted to know “the world”. A few years afterwards, in 1983, he went to Khartoum. He also sought schooling in the capital city.

While he was working for an Arab merchant, the man told Nhial Biel that he would become his brother if would agree to stay with his dead father’s second wife. Nhial Biel refused the offer of the Arab. He was infuriated at Nhial Biel’s refusal and threatened to kill him.

That night, Nhial Biel was terrified of being killed. He had a dream which he saw a big light that lit up all the room and heard a voice that told him: “My son, do not worry. I am with you. You will not die.” He identified that voice as the voice of his father Manyuon Biel. He thought that the light was the light of God, the presence of the true God who protected him from death.

In fact, he escaped from the Arab’s house. He understood later that the intentions of the Arab were not good; he wanted to keep him as his slave. After that dream Nhial Biel decided to become a Catholic and joined the catechumenate in Kosti. He quickly learned the basic principles of the Catholic faith and even before he was baptised, started teaching other Nuer what he had learned about God, the Church and some prayers. He was baptised on 29 March, 1986, in Kosti. A Comboni Missionary baptised him with the name of John.

He became an energetic, charismatic and tireless catechist in Kosti, Khartoum, Sennar and Wad Medani. In 1988, during the solemnity of the Assumption of Mary, he was leading a big march in. Kosti from one of the chapels to the parish church. The security forces stopped him. He was taken to the jail and interrogated about his activity and teaching.

When the Catholic community knew that their catechist had been arrested, they went all together to the compound of the police and asked for his release. They arrived marching and carrying their flags and crosses. The police freed him but strongly advised him not to teach again. But he was not afraid of the warnings of the police and he continued preaching and teaching.

He returned to Southern Sudan in 1991. He became the head master of a primary school in Pomalual, near his home village. The local authorities told him that he was going to receive a military rank because he was working in an SSIM’s school. He could not work just as a civilian. He had to join the movement. He received the rank of sergeant mayor, even though he wanted to teach as a civilian.

In 1993, the Catholics of Nyal learned that John Nhial Biel was a catechist in Khartoum and asked him to become their catechist. The Catholics of Nyal went to the SSIM authorities and asked them to release John Nhial Biel to be their catechist. They agreed with the request of the Catholic community and John became the catechist of Nyal in 1993.

Under his leadership the Catholic Church became very strong in all the area of Nyal, Nyuong. Catechist Joseph Pal Mut who was the leader of the Catholic Church in the rural Western Nuer, appointed Catechist John Nial Biel as the regional catechist in charge of the Nyuong area and authorised him to baptise. The Catholic community built him a compound and cared for his basic needs and those of his family. He got married in Church to his wife Angelina Nyariaka on 24 July 1996.

He is a natural leader respected and loved by the Catholics of his area. They see him as their father in the faith and the spirit. He was the chairman of the Saint Joseph Parish Regional Catechists Committee for some years. He has extended his ministry beyond his home area to all over Western Upper Nile and is very well known by Catholics and non-Catholics alike and even by the local authorities.