However, by studying hard after work each day, David was able to secure a position as a teacher at Glasgow High School in 1845. And in the same year, he married Christina Orr who had also been living and working at New Lanark, as a cotton reeler. By the following year, David had his own small school - West Muir - in the Parkhead area of Glasgow. At the time of the 1851 census, the Mallochs were living near the school with their 5-year-old son William. Soon afterwards, David decided to "go in for the ministry" and entered Glasgow University to study towards this ambition. Upon completion of his studies he was appointed as a missionary in St. Michael's U.P. Church in Greenock (1 July 1896 Dundee Courier).
"In the thirteenth year of his ministry, Mr Malloch had the pleasure of seeing the handsome church the U.P. congregation now worship in opened."
At a cost of £1,200 the new church replaced its century-old predecessor that had been built with the help of local people who had carried stone from the beach in barrows, creels and aprons. The stone plaque built into the front elevation bears the year of construction (1871) and the initials of David Malloch (D.M.) - see below.
David Malloch's last significant public appearance was at the opening of the Lundin Golf Club House on 4 April 1896 "when he led off the refrain 'He's a Jolly Good Fellow' when Mr Gilmour's health was proposed". He preached his last sermon on 3 May 1896 and died on 29 June at the manse. He was survived by his wife, three sons and one daughter (although the Mallochs had at least seven children in total).
The St Andrews Citizen on 4 July described his "genial buoyant spirits" and the fact that he was "conspicuous throughout the parish by his locks and shaven face, which seemed to savour more of art than the pulpit". Also noted was that "he never conducted a service in his church without remembering in his prayers those who went out into the deep in ships" - making him a "special favourite" of the fisher folk.
A wall plaque was placed on the wall inside the church to his memory which read:
"For 36 years (he) went out and in among them, speaking words in season to the weary and comforting the afflicted, while his Christian qualities and generous sympathies won for him the esteem and reverence of his flock and of all who knew him."