A return to New Zealand saw him hold down a succession of jobs long enough to earn a fare to the United Kingdom.

During the time at College, Riddell was involved in protest against the 1981 South Africa rugby union tour of New Zealand.

The family moved to Switzerland in 1982, where Riddell pursued postgraduate studies in Theology at an international seminary near Zurich, graduating summa cum laude at the end of 1984.

Riddell returned to New Zealand, and was ordained and appointed minister of Ponsonby Baptist Church, a small congregation in the central city.

He held a variety of jobs concurrent with that of minister, as a journalist for New Outlook, a current affairs journal, and later as a part-time lecturer at Baptist College.