Since 1983, he has been a full-time missionary with the Brethren in Christ Church with a focus on apologetics and polemics among the Muslims of London.

[1][2] He earned a BA from Messiah College and then a Masters of Divinity from Eastern Baptist Theological Seminary in apologetics.

In 1981, while studying for his masters, Smith attended a seminar on Islam while noting that there were only 1,500 Christians ministering to Muslims worldwide, he decided to become a missionary to the Muslim world and pursued a second master's degree in Islamic studies from Fuller Theological Seminary.

[1] In 2010, Smith resumed work on his PhD at the Melbourne School of Theology which he completed in March 2017.

Smith also engages in formal public debates with prominent Muslim apologists and scholars including Omar Bakri Muhammad, Azzam Tamimi,[3] Shabir Ally,[9][10] Anjem Choudary,[4] Abdur Raheem Green[6] and Edip Yüksel.