He entered the Church of England in 1856, a fact attributed by his former tutor William Farrer (1820–1908) to the influence of Clark's wife.

From that date to the time of his death he held the title of Emeritus Professor and as such he sat ex officio on the Council of Trinity College.

Following his death, the Corporation of Trinity College, at its annual meeting on 21 November 1912, adopted a resolution recording the great debt of gratitude it owed to Professor Clark.

The resolution proceeded to say : — "As a Preacher and public Lecturer, Professor Clark was very highly esteemed, and his many engagements in these capacities served to make Trinity College favourably known far and near.

He showed remarkable versatility and brilliancy in his work, both in the class room and on the public platform, as well as in his literary productions, which embrace Theology, History, and Literature.

Dr. Clark's singular devotion to Trinity College and the great ability with which he served it, entitle him to the lasting regard of all its supporters, while his inexhaustible human sympathy and kindness of heart ensure for him the grateful and affectionate remembrance of a host of friends."