John Greer was bought up in a Christian home and within a Presbyterian family. He was converted at the age of fifteen and brought into Ballymena Free Presbyterian Church soon after. At the age of eighteen, he began to sense the leading of the Lord to the Gospel ministry, entering the Theological Hall a few years later in October 1974.
In June 1975, Mr Greer was placed as Student Minister in charge of Sixmilecross Free Presbyterian Church, being later called by the congregation at the close of his years of study. He was ordained by Presbytery to the Gospel ministry in December 1978, remaining in Sixmilecross until March 1983. During his tenure in Sixmilecross, the Lord blessed the work in various ways, including the erection of the church building that continues to serve as the meeting place of the congregation there.
The conclusion of Mr Greer's ministry in Sixmilecross in 1983 was due to the call of God to go to the fledgling church in Philadelphia, USA. The move also meant an end to teaching New Testament Greek in the Whitefield College of the Bible and editing Truth For Youth, the denomination's youth publication. But, knowing the leading of God, Mr Greer, with his wife and three children, moved to a new land and a new work to pioneer the Free Presbyterian witness.
Over the years of ministry in the work in Philadelphia, the Lord saw fit to bless, especially in the final ten years when the work was established more and more. Starting out in one suburb in Philadelphia, namely Newtown Square, the work later moved to its present location in Malvern.
Mr Greer's American ministry came to a close in August 2000, when he moved back to Northern Ireland with his wife and family. This new phase of ministry was to take him back to his home town of Ballymena and to his home congregation, to succeed the Rev. James Beggs upon his retirement. Mr Greer was installed as Minister of the Ballymena congregation on 31 August, 2000. As well as pastoring the congregation, he has served in the recent past as the Moderator of the Ulster Presbytery, and currently teaches Systematic Theology in the Whitefield College of the Bible. Over these past years, the Lord has given some blessing to the Ballymena Church as it seeks to stand for Christ in a day of present darkness.