In 1953 Willie Mullan was called to Lurgan Baptist church, and in August of that year he commenced the work in Lurgan. One of his great accomplishments during this time was the Tuesday night Bible class. Every Tuesday night hundreds attended to hear the exposition of the Word. In 1957 William Hewitt and a team of helpers commenced the tape recordings of the Bible class. At least 1500 of these recordings remain until this day. Willie Mullan not only preached in Northern Ireland but in many countries across the world. His ministry has also spread world wide through the use of the audio tapes.
In December 1980 Willie Mullan died after taking his own life. On Boxing day that year, his bodily remains were laid to rest in his home town of Newtownards.