The dioecese of Chelmsford said he died peacefully in his sleep at home in the early hours of 25th July 2017. He was diagnosed with the disease in 2014.
Bishop John said at the time of his installation as Bishop of Bradwell in 2012 that he believed the Church of England needed to "reach out and change society". He unpacked this theme in his 2016 Lent lecture when he said: "Ministry is not about serving the Church. It is about serving God in the world".
Stephen Cottrell, the Bishop of Chelmsford, has said: "Bishop John was a wonderful servant of the gospel and a fantastic colleague.
"As an archdeacon in Wiltshire he was known to be dependable and creative. As a bishop serving in this great diocese of Chelmsford these qualities blossomed and bore fruit as he helped take forward our diocesan vision for growth and renewal.
"He quickly won the confidence of the clergy and the love of the people he served."
Bishop Stephen said Bishop John was determined to carry on with his ministry despite the obvious shock of his diagnose.
He continued: "Bishop John just got stuck in, teaching the Christian faith, visiting the parishes he served, and refining his understanding of the gospel so that his life now matched his ministry in a way that was humbling and inspiring to experience.
"He not only spoke about the wonderful inclusive hospitality of God's love, he lived it to the last. I could not have wished for a better colleague. We will miss him hugely."
Bishop John called for change in the Church especially in the encouragement of vocation among people God is calling to ministry.
In a blog on vocations in October 2016 he wrote: "the Church and its processes... need radical change to value and create space for those whom God is calling".
Bishop John was very encouraging to young people and young adults. The Encounter scheme in Chelmsford Diocese, which has given young people an opportunity to explore their vocation, was his initiative.
He served as the Chair of the Chelmsford Diocesan Board of Education, acted as a mentor to a group of young disciples, and hosted Take Over Challenge days with young people.
He leaves a widow, Gillian, and four children.
The arrangements for Bishop John's funeral will be announced in due course.
