Team Biographies

Michael Ramsden

Michael Ramsden is President of RZIM and one of the founders of OCCA The Oxford Centre for Christian Apologetics. He spent most of his childhood in the Middle East and later moved to the UK, where he worked for the Lord Chancellor’s Department investing funds. Michael went on to teach jurisprudence at the University of Sheffield, whilst doing research in law and economics.

His passion is to engage with people of all backgrounds and cultures about questions of faith, which he has been doing for over twenty years. He speaks in business, academic, political, and other settings around the globe, ranging from Europe and the Middle East, to Asia and the Americas. Michael helps oversee the international team of RZIM speakers based in sixteen offices worldwide. He and his wife, Anne, have three children and are based in Atlanta.

Dr Amy Orr-Ewing

Dr. Amy Orr-Ewing is President of OCCA The Oxford Centre for Christian Apologetics and a Senior Vice President with Ravi Zacharias International Ministries. She leads a team of pioneering apologist-evangelists and speaks around the world on how the Christian faith answers the deepest questions of life.

Over the last twenty years, Amy has spoken on university campuses, including Oxford, Cambridge, Vienna, Hong Kong, Phoenix, Massachusetts, in the Speakers Rooms and Chapel at the UK Parliament, on Capitol Hill, and to West Wing staff at the White House. She also speaks in banks, businesses, and consultancy firms as well as churches and conferences.

Amy gained a first-class degree in Theology and a DPhil (doctorate) from the University of Oxford. She is also the co-founder of REBOOT, a youth apologetics initiative aimed at helping young people think deeply about faith, which now runs in countries all over the world.

Amy is married to Frog and helps lead Latimer Minster, a church plant and community on a farm in Buckinghamshire, and they have three children.

Areas of interest:  the nature of truth, identity, rational defence of Christianity, historicity of the Bible, New Testament history, ethical dilemmas, tolerance, evil, suffering, friendship, human trafficking.

Amy has made various appearances on national television in the UK  including appearances on BBC  Television (Blue Peter and Songs of Praise) and television networks in the USA. She is increasingly called upon to comment on a variety of topics relating to the Christian faith on radio interviews both across the UK and worldwide.  She has contributed to various discussions including the BBC Radio 4’s Beyond Belief.

Dr Tanya Walker

Tanya Walker is Director of OCCA The Oxford Centre for Christian Apologetics, and Director of Speakers for RZIM Zacharias Trust.

She holds a PhD in Politics and International Studies from SOAS (University of London) where her thesis focused on notions of freedom, power, and the complexities at the interface of competing rights within a liberal framework. Tanya also has an MA in Islamic Societies and Cultures from SOAS and an undergraduate degree in Politics, Philosophy, and Economics from Christ Church, Oxford University. Prior to undertaking her postgraduate research, Tanya worked in the political sphere in various public policy and communication roles.

Born in the Middle East, and from Armenian descent, Tanya grew up against the formative backdrop of a persecuted church. Her passion is to connect with people from all walks of life in exploring the ultimate questions of life and meaning. Specifically, the mysterious claim of the Gospel that the Christian narrative not only provides a compelling framework through which to make sense of our world and our experiences, but is the context through which we can encounter God.

Tanya speaks internationally in academic, business, and political contexts, as well as Christian gatherings, alongside raising outstanding Christian thinkers and communicators through the OCCA programme. Tanya is married to Toby and they are based in Oxford with their three young children.

Dr Sharon Dirckx

Dr Sharon Dirckx is a Senior Tutor at OCCA The Oxford Centre for Christian Apologetics and an RZIM Apologist. Originally from a scientific background, she has a Ph.D. in brain imaging from the University of Cambridge and has held research positions at the University of Oxford, UK and the Medical College of Wisconsin, USA.

Sharon is an OCCA Alumna, and completed the OCCA programme in 2005 during its founding year. She is invited to speak and lecture in a variety of contexts across the UK, including the 2014 Veritas Forum at the University of Oxford.

Sharon has also appeared on BBC Songs of Praise, Justin Brierley’s programme, Unbelievable, on Premier Christian Radio, BBC Radio 2 Good Morning Sunday with Clare Balding and BBC Radio 4 Beyond Belief. Her topics of interest focus on the interaction of belief in God with Science, and with the problem of evil and suffering.  Her book, Why?: Looking at God, Evil and Personal Suffering, won the prize for best book at the 2014 Speaking Volumes UK Christian Book Awards (presented by Pam Rhodes). Why? interweaves the stories of people who have suffered, with a practical look at some ‘Why?’ questions on suffering.

Sharon lives in Oxford with her husband and two young children.

Tom Price

Tom Price is a Senior Tutor at OCCA The Oxford Centre for Christian Apologetics and an apologist for RZIM. He studied Philosophy at university and later completed an MA in Christian Apologetics.

In recent years Tom has spoken at universities and churches in Hong Kong, Europe, South Africa, USA and other places across the world. In the UK, he has provided teaching for major conferences such as Keswick, Spring Harvest and BMS Catalyst. He lectures for HTB School of Theology and is regularly involved in outreach alongside OICCU and other Christian Unions. Additionally, Tom has written for various media outlets and has appeared on Premier Christian Radio’s ‘Unbelievable?’.

Tom was previously the Founding Editor of UCCF’s website Tom is interested in worldview, culture, theology, missiology, apologetics and philosophy of religion broadly. He is passionate about mission that engages with where people really are and the serious questions and objections they have about religious beliefs. Tom is married to Caroline, has young children, and they live in Oxford.

Simon Edwards

Simon Edwards is the Lead Missioner for OCCA The Oxford Centre for Christian Apologetics. He holds separate degrees in law and economics from the University of Queensland, Australia, as well as graduate diplomas in legal studies and education. Simon also has a postgraduate diploma in theology from the University of Oxford and is currently studying for a master’s degree in divinity at the University of St Andrews. He brings with him a diverse range of Christian ministry, legal, government, and teaching experience. Prior to joining RZIM, Simon lived and worked in Australia as a lawyer, specialising in private practice in commercial law and in government practice in constitutional law. He also worked for two years in a secondary school as a religious education teacher.

Simon is a regular speaker in many different settings, including at evangelistic and apologetic training events in universities, schools, churches, and workplaces both in the UK and abroad. He has also been invited to speak on a number of BBC Radio programs regarding the evidence for the Christian faith, particularly from his perspective as a lawyer. Simon’s areas of interest include moral apologetics, human dignity, faith and reason, the nature of truth, evidence for the resurrection, suffering, and ethics. Simon is married to Natasha, who is part of the leadership team at Latimer Minster, a missional Church of England church situated between London and Oxford. Simon and Natasha live in High Wycombe with their three young children, Grace, Jonathan, and Joseph.

Dr Os Guinness

Os Guinness is an author and social critic. Great-great-great grandson of Arthur Guinness, the Dublin brewer, he was born in China in World War Two where his parents were medical missionaries. A witness to the climax of the Chinese revolution in 1949, he was expelled with many other foreigners in 1951 and returned to Europe where he was educated in England. He completed his undergraduate degree at the University of London and his D.Phil in the social sciences from Oriel College, Oxford.

Os has written or edited more than thirty books, including The Call, Time for TruthLong Journey Home, Unspeakable, A Free People’s SuicideThe Global Public Square, and Renaissance. His latest book Fool’s Talk – The Recovery of Christian Persuasion was published by InterVarsity Press in June, 2015.

Before moving to the United States in 1984, Os was a freelance reporter with the BBC. Since then he has been a Guest Scholar at the Woodrow Wilson Center for International Studies, a Guest Scholar and Visiting Fellow at the Brookings Institution, and Senior Fellow at the Trinity Forum and the EastWest Institute in New York. From 1986 to 1989, Os served as Executive Director of the Williamsburg Charter Foundation, a bicentennial celebration of the First Amendment. In this position he helped to draft “The Williamsburg Charter” and later “The Global Charter of Conscience,” which was published at the European Union Parliament in 2012. Os has spoken at dozens of the world’s major universities, and spoken widely to political and business conferences on many issues, including religious freedom, across the world. He is currently a senior fellow at OCCA The Oxford Centre for Christian Apologetics in Oxford, though he still lives with his wife Jenny in the Washington DC area.

Ravi Zacharias (1946 – 2020)

Ravi Zacharias founded The OCCA in 2004 with the help of Professor Alister McGrath, the RZIM team and the staff at Wycliffe Hall, a Permanent Private Hall of Oxford University, where Zacharias was an honorary Senior Research Fellow between 2007 and 2015.

Over the years, OCCA has trained over 400 students from 50 countries who have gone on to carry the gospel in many arenas across the world. Some have continued to follow an explicit calling as evangelists and apologists in Christian settings, and many others have gone on to take up roles in each of the spheres of influence Zacharias always dreamed of reaching: the arts, academia, business, media and politics.

Zacharias spent 48 years commending the Christian faith and addressing life’s great existential questions of origin, meaning, morality, and destiny with eloquence and grace. He fully believed the truth of Jesus Christ can endure the toughest critiques and philosophical attacks. He authored or edited over 25 books in the fields of theology, apologetics, comparative religion, and philosophy.

On May 19, 2020, Zacharias died at the age of 74 following a brief battle with sarcoma. He is survived by his wife of 48 years, Margie; daughters, Sarah and Naomi; son, Nathan; and five grandchildren.

“The training offered by the OCCA is designed for men and women serious about integrating their commitments to Christ with their professional lives. Drawing people from the business world, academia and the arts, the OCCA fosters an engaging and effective style of evangelism, undergirded by a framework of sound apologetics.”
– Ravi Zacharias

Updated October 15th, 2020

Please note that this bio may not be distributed or edited without the express written permission of RZIM. Thank you.

Rev Professor Alister McGrath

Alister McGrath is the Andreos Idreos Professor of Science and Religion at the University of Oxford. He was the Founding President of OCCA The Oxford Centre for Christian Apologetics. His previous posts include being Professor of Theology and Education at King’s College, London, and Professor of Historical Theology at Oxford University.

McGrath gained first class honours from Oxford University in Chemistry (1975) and first class honours in Theology (1978). He holds an Oxford DPhil (1978) for his research in molecular biology, a DD from Oxford University’s Faculty of Theology for his work in historical and systematic theology (2001), and a DLitt from Oxford University’s Division of Humanities for his research in science and religion (2013). He was elected FRSA in 2005, in recognition of his work as a public intellectual. A former atheist, he has established a reputation as one of the leading apologists for Christianity, as well as one of the world’s most respected Christian theologians. His many books include a new highly acclaimed biography of CS Lewis, a series of market-leading textbooks in Christian theology, and some best-selling books engaging with the “New Atheism”.

“Under God’s grace, we seem to have gone from strength to strength since our founding and we are looking to the future with eager anticipation. Every year that passes reinforces the need for the church to have leaders who are skilled in the art and science of commending and defending the Christian faith, and passing on those skills to their congregations.”
– Prof Alister McGrath

Visit Alister’s website at