Michael Griffiths, who died on 9 January aged 93, was one of the 20^th century's most dynamic and influential mission leaders. He was born in Cardiff in 1928.

After graduating from Cambridge in natural sciences, Mike trained for the Anglican ministry at Ridley Hall; however he wasn't ordained as he found himself at variance with Anglican teaching on infant baptism.

Throughout his student years, there was always a pull towards world mission, and after two years as a Christian Union staffworker, he and his wife, Valerie, sailed for East Asia, joining the Overseas Missionary Fellowship (now OMF International). They would serve first in Japan.

Valerie, an Oxford graduate, brought the same passion to this calling as Mike, and, as one OMF colleague commented, it was impossible to think of Mike without Valerie. They were Mike-and-Valerie throughout their ministry.

Mike wrote easily and fluently, especially for students and young graduates. His 25 books included Cinderella with Amnesia (1975) which asked whether the church had lost her memory, and her biblical calling to mission. Give up your small ambitions (1970) and Tinker, Tailor, Missionary (1992) both urged graduates to think and pray about mission service. Lambs dancing with wolves (2001) examined the experience of entering a new culture. Griffiths was a thinker, a realist, and could be hard-hitting, but always with a scriptural basis and pastoral application.

His leadership gifts, and his capacity for hard work were clear from the outset. At the age of 38 he was approached to lead the mission, and he took over as General Director in 1969, aged 41. These was a period of massive change. The mission had been founded by an Englishman, Hudson Taylor, as the China Inland Mission. When Mike took over as General Director, it was working in ten countries, and Asians were being drawn in as members, with Indonesians and Singaporeans working in the Philippines alongside North Americans and Germans; and Koreans working in the same international teams in Indonesia or Japan or Hong Kong. World mission was gradually becoming global, and the old paradigm of 'the West to the rest' was being eroded for good.

Mike was a visionary, always dissatisfied with what was, and wanting better. At his side was Denis Lane, who had trained in law, bringing sound judgment to the administration of the mission.

In April 1974, Mike received a ransom demand, addressed to him personally, from South Thailand. Two OMF nurses had been abducted. Minka Hanskamp from the Netherlands, and Margaret Morgan from Wales lovingly nursed leprosy patients in a rural clinic. They would be released for the payment of half a million dollars, on the condition that OMF persuade Israel to withdraw troops from the West Bank.

Each part of this demand was impossible. OMF did not get involved in politics and no ransom payment could be countenanced, as the women themselves would willingly have understood. Any ransom payment would have made every other missionary vulnerable to kidnapping. Negotiations continued, but to no avail. The nurses' bodies were found almost a year later. They had been shot in the head several months earlier without the mission being informed. It was a dreadful time.

Three months after the kidnap, a call came to send missionaries into Cambodia. There was foreboding in the air, as Pol Pot and his Khmer Rouge were set to take power in the land. Christians would suffer dreadfully. Griffiths met with his senior team. The mission was at full-stretch already; and anyone going into the country may not come out alive. There was hesitation from his senior leaders. Wrestling with lack of support from a team, and knowing of the real mortal danger which workers could face is never easy.

Griffiths persuaded the leadership that they should provide help, but ask for unmarried volunteers only, so no OMF children would be orphaned by losing parents. A small team entered Cambodia, with a window of only ten months before Phnom Penh fell. The story is told in Don Cormack's compelling book Killing Fields, Living Fields (1997).

Mike moved into theological education in 1980 as Principal of what is now London School of Theology, with Valerie teaching Old Testament. From 1989 until his retirement in 1992, he and Valerie taught at Regent College, Vancouver, where Mike was appointed to the first chair in Mission Studies. Here he joined three other British evangelicals on the faculty: Jim Houston, Michael Green and J I Packer, old friends whom Valerie had known since her Oxford days.

For as long as he had strength, Mike continued to write, leaving unpublished work which will be of value to researchers. His leadership and influence will no doubt become the subject of doctoral theses in time to come. In the words of Daniel 12:3, he will 'shine like a star as one who has led many to righteousness'.

Mike leaves his wife, Valerie, four children and their families.

A thanksgiving service will be announced.

Julia Cameron served on OMF staff in the 1990s. She runs Dictum Press, a small independent publishing endeavour, based in Oxford.