For 27 years 'Willie' Mullan taught the largest Bible class in the United Kingdom, which was a source of great encouragement to many believers. Thousands attended these classes in Lurgan Baptist Church. The voice of Willie Mullan has been heard in almost every country, he preached extensively in Great Britain and also Faeroes, Germany, Greece, Palestine, Syria and Canada. At that last day, many thousands shall testify that it was through the preaching of Willie Mullan that they found the Saviour.