Fr. Gerry began his missionary journey in the southern Philippines on Mindanao, where he spent time working in a parish for a number of years before moving into hospital ministry. Following his time there, he was assigned to the U.S. in Philadelphia where he became involved in vocation and mission education promotion.
In 1986, at the age of 40, he began the study of mandarin in Taiwan but had to leave unexpectedly after a year and a half due to illness. Returning to the Philippines, he spent the next four years in parish work, but his poor health continued. Returning home to Ireland, he worked in an area of Northern Ireland in Derry City for eighteen months whilst recuperating, after which time he was assigned to the U.S. undertaking Spanish studies for a period of time before moving on to work in California, Texas and New York. There his involvement included both parish work and mission promotion. Part of this saw Gerry assigned to work in a parish in Mexico; Cuidad Juarez.
This was followed by a nine year spell undertaking mission promotion in Ireland before moving to Chile in 2011 for three years. There, Gerry was based in a parish where he was primarily involved in both prison and hospital ministry. In 2015 Gerry was appointed to the British region and since that time has been working on the Mission Awareness Team, initially up in Scotland, and now in England & Wales.