One Rock Team Members

Mark Williamson

Mark Williamson

Co Director

Mark Williamson is one of the founders and co-directors of One Rock. He leads the curriculum development on Discerning Vision and Leadership Skills, and coordinates the work across Africa. He has written biographies on John Wesley and William Wilberforce. Outside of One Rock he is an Associate Minister with Fresh Expressions, and leads the Prayer for London movement. He supports Liverpool FC, loves talking about good films, and going for long walks with his wife Joanna.

Joanna Williamson

Joanna Williamson

Co Director

Joanna is a co-founder and co-director of One Rock. She leads on the curriculum development in the areas of Spiritual Formation and Global Mission, and also on partnerships in the United States, Latin America and Asia. She is the author of biographies on Hudson Taylor and Amy Carmichael. Outside of One Rock she is a trustee of Renovare Britain and Ireland, and a lecturer at Westminster Theological Centre. She is currently completing her Doctorate at Asbury Theological Seminary. She loves nature, travel and learning languages. If she could she would love to have a German Shepherd and take him for long walks.
Geoff Elliott

Geoff Elliott

Associate Trainer

Geoff took early retirement from Mars Corporation several years ago, and now leads One Rock training workshops on leadership and coaching. A former Mars Associate, he held several senior leadership positions in the organisation, including overseeing their business in Greece and in Poland. His final position was Human Resources Director for their Asia Pacific region. When not training leaders Geoff enjoys playing golf, reading history and supporting Wolverhampton Wanderers FC.
Marcel Bonfim

Marcel Bonfim

IT Consultant

Marcel advises on all the IT issues related to One Rock, and acts as lead consultant in the development of our online Learning Academy. Based in Curitiba, Brazil, he also supports much of the training that takes place across that nation. Marcel is founder and director of History Makers, a web development and IT solutions company that serves churches and ministries in their communications.
Joy Da Costa

Joy Da Costa

Prayer Coordinator

Joy coordinates the prayer for the work of One Rock. She sends out the Pebbles prayer updates to our supporters, and takes a lead role in evening prayer meetings we hold for the work. Alongside prayer, she is passionate about helping people to discern more clearly God’s vision for their lives. She works for the Kahaila missional cafe in east London, and is excited about living out her own vision when she launches a similar cafe in the City of London in 2016.
Kerry Purselle

Kerry Purselle

US Team Leader

Kerry is the US Team Leader, coordinating our work in the United States. A retired United Methodist pastor, she loves spending time with her grandchildren, but also finds time to volunteer for several other causes. She served time as a missionary in Warsaw, Poland, and now resides in North Carolina.

Board Members

One Rock is governed by a Board of Trustees; current members are Peter Calderbank, Antoinette Daniel, Luke Hamlyn, Andy Dipper, Frances Miles and Abby Herring.

Peter Calderbank

Peter chairs the One Rock board. He is the chief executive of Field Lane (www.fieldlane.org.uk), a charity providing housing, care and support services to meet the needs of vulnerable families and individuals. He has a wealth of experience in the UK charity sector, both as a trustee and as a chief executive.

Antoinette Daniel

Antoinette is founding director of Just Helpers (www.justhelpers.co.uk), an ethically-focussed, London-based cleaning company. She has formerly worked as a netball coach, and as director of an anti-trafficking organisation raising awareness about modern day slavery happening in London.

Luke Hamlyn

Luke is a freelance worship leader, facilitator and musician (www.lukehamlyn.co.uk). He regularly leads worship at his home church (Bless Community Church in West London) and for the A Call To Business network. He has played regularly alongside such worship leaders as Andy Flannagan and Noel Robinson.

Andy Dipper

Andy is the principle of All Nations College (www.allnations.ac.uk), training Christians for mission in a multicultural world. Previously he is worked as Chief Executive of Release International, as Chief Executive of Viva, and also for Tearfund. He advises One Rock on international mission.

Frances Miles

Frances is Head of Giving at Stewardship (www.stewardship.org.uk), a UK charity that’s transforming generosity by making giving easy, inspiring greater generosity and strengthening Christian causes. Frances brings great experience on UK charity law, and the realm of fundraising.

Abby Herring

Abby is an entrepreneur, a youth worker and a baker. She works as a freelance (and excellent!) cake baker, a volunteer youth leader with her local church, and a part time cafe worker. Her dream is to open a missional cafe. She is an alumni from the very first Academy of Spiritual Leadership run by One Rock.

In the United States One Rock is a registered 501(c)3. Board members are Scott Stover, Rev Kerry Purselle, James Fillingame, Joanna Williamson and Mark Williamson.