In February 1970, David Cross and his wife Barbara, together with their two young children, Shannon and Shelly, arrived in Brookton Western Australia under the auspices of World Presbyterian Missions (now Mission to the World or MTW). The Cross' came to Brookton to assist in ministering to the aboriginal community there and in the surrounding areas. Additionally, David planted a church in the Caversham Hall with members of a Bible study group he had been leading at the home of Andrew and Joyce Priddle. The name, Westminster Presbyterian Church (WPC)was decided upon and the first meeting was held in December 1970. At that time, WPC Australia was started and a mission family became a church planting family. This church would become the current Maida Vale WPC. Two additional churches were started, ultimately becoming Kingsley WPC and Bull Creek WPC. The Cross family returned to the USA in 1981 where David became the organising pastor for a church in Carlisle, Pennsylvania.

In 1990 David and Barbara accepted an invitation to help the newly developing Evangelical Presbyterian Church in England and Wales (EPCEW) with their church planting efforts. After raising support in the US and Canada, as well as Australia, they arrived in Chelmsford, Essex, England in 1992 and spent 10 years developing the EPCEW congregation there. During that time David became the Clerk of Presbytery as well as the pastor of the local church and the chairman of the church planting committee of presbytery. He also helped with the writing of the Book of Order for the new denomination.

Since the Chelmsford church has called a British (actually Irish) Minister the Crosses have moved to Worcester with a view of helping other men to plant churches in England and Wales. They have assisted in Cheltenham, Neath (Wales) and Solihull (a Birmingham suburb).

David served as the editor of the denomination's publications, Presbyterian Network and PRAY for one another until recently, when he took up a new role through MTW. More and more of their ministry seem to be helping others to do ministry. David is the MTW Country Coordinator for England and Wales. The ministry will involve working with existing denominations, churches, MTW teams, and other like-minded agencies. It will also involve recruiting suitable new workers and assisting the assimilation of those people into their appointed place of service. Barbara is part of the MTW Europe Care Council with particular responsibility for 49 women working in Central and Eastern Europe.