In May, 1744, Dr Erskine was ordained minister of Kirkintilloch, in the presbytery of Glasgow, where he remained until the year 1753, when he was presented to the parish of Culross, in the presbytery of Dunfermline. In June, 1758, he was translated to the new Grey Friars, one of the churches of Edinburgh. In November, 1766, the university of Glasgow conferred on him the honorary degree of doctor of divinity, and in July, 1767, he was promoted to the collegiate charge of old Grey Friars, where he had for his colleague Dr Robertson.

In the different parishes in which Dr Erskine had ministered, he had enjoyed the esteem and affection of his parishioners. They were proud of him for his piety, learning, and rank;—they were delighted and improved by his public and private instructions, and they deeply lamented his removal when called from them to undertake the more important charges to which his merit successively promoted him. His attention to the duties of the pastoral office was most exemplary, and his benevolent consolation and advice, which were at the service of all who required them, secured him the respect and affection of his flock, who long remembered him with feelings of the warmest gratitude. No man ever had a keener relish for the pleasures of conversation; but in these he considered, that he ought not to indulge, conceiving his time and talents to be entirely the property of his parishioners. At college, he had made great attainments in classical learning, and through life, he retained a fondness for the cultivation of literature and philosophy, in which his great talents fitted him to excel; he refrained, however, from their pursuit, restricting himself in a great measure, to the discharge of his important religious duties. But although literature was not allowed to engross a large share of his attention, nor to interfere with his more sacred avocations, still, by much exertion, and by economizing his time, he was enabled to maintain a perfect acquaintance with the progress of the arts and sciences.

Perhaps, no country in the world ever made more rapid progress in literature than Scotland did during the last half of the eighteenth century. And it is to Dr Erskine chiefly, that the nation is indebted for that improvement which took place in our theological writings, and in the manner in which the services of the pulpit were performed. Previous to the time when he was licensed, sermons abounded with discursive and diffuse illustrations, and were deformed by colloquial familiarities and vulgar provincialisms; and although the discourses of such men as Robertson, Home, and Logan, and others of their contemporaries, were conspicuous for their beauty, still it is to the published sermons of Dr Erskine, that the perspicuity and good taste subsequently displayed in the addresses from the pulpit have been justly traced. Even before the publication of his sermons, however, Dr Erskine had been favourably known to the public. His first publication was a pamphlet against certain of the doctrines contained in Dr Campbell’s work, on the "necessity of revelation." In this production, Erskine had occasion to advocate some of the opinions maintained in Dr Warburton’s Divine Legation of Moses; and having presented that distinguished prelate with a copy of the pamphlet, a correspondence ensued, highly creditable to Erskine, from the terms in which Warburton addresses him; more particularly when it is considered that at this time Erskine had not attained his 21^st year.

About the time when Dr Erskine obtained his license, a remarkable concern for religion had been exhibited in the British colonies of North America. In order to obtain the earliest and most authentic religious intelligence from those provinces, he commenced a correspondence with those chiefly concerned in bringing about this change; nor was this correspondence confined to America. He also opened a communication with several divines of the most distinguished piety on the continent of Europe. This intercourse he assiduously cultivated and carried on during the whole of his life. One bad consequence of it was the toil which it necessarily entailed on him, not only in answering his numerous correspondents, but in being called upon by the friends of deceased divines, to correct and superintend the publication of posthumous works. To his voluntary labours in this way, the religious world is indebted for the greater part of the works of president Edwards, and Dickson, and of Stoddart, and Fraser of Alness. Such was Dr Erskine’s thirst for information concerning the state of religion, morality, and learning on the continent, that in his old age, he undertook and acquired a knowledge of the Dutch and German languages. The fruits of the rich field which was thus thrown open to him appeared in "The Sketches and Hints of Church History and Theological Controversy, chiefly translated or abridged from modern Foreign Writers. Edinburgh, vol. 1st, 1790, vol. 2nd, 1799." These volumes contained the most extensive and interesting body of information respecting the state of religion on the Continent, which had been presented to the world.

One of the objects professed by the promoters of those revolutionary principles, which, towards the close of the last century threatened the subversion of social order in Europe, was the destruction of all christian church establishments; and an association was actually formed on the continent for this purpose. Dr Erskine, however, having in the course of his researches into the state of religion, discovered the existence of this association, gave the alarm to his countrymen; and professor Robinson and the Abbe Barruel soon after investigated its rise and progress, and unfolded its dangers. The patriotic exertions of those good men were crowned with success. Many of those who had been imposed upon by the specious arguments then in vogue, were recalled to a sense of reason and duty; and even the multitude were awakened to a sense of the impending danger, when the true character of the religion and morality of those political regenerators, who would have made them their dupes, were disclosed and illustrated by the practical commentary which the state of France afforded. The consideration that he had assisted to save this country from the horrors to which the French nation had been subjected, was one of the many gratifying reflections which solaced Dr Erskine on looking back, in his old age, on his laborious and well spent life.

Dr Erskine’s zeal in the cause of religion led him to take a large share in the business of the society for the propagation of christian knowledge; and even when, through the infirmities of bad health and old age, he was unable to attend the meetings of that body, such was the dependence of the directors on his information and sound judgment, that on any difficulty occurring in the management of their affairs, they were in the habit of consulting him at his own house. In the general assembly of the church of Scotland, he was for many years the leader of the popular party; there the openness and integrity of his character secured him the confidence and affection of his friends and the esteem and respect of his opponents. The friendship which subsisted between him and principal Robertson, the leader of the moderate party, has been objected to by some of his more rigid admirers, as displaying too great a degree of liberality—a fact strongly illustrative of the rancour which existed in former times among the high church party. The courtesy which marked Dr Erskine’s conduct to principal Robertson throughout their lives, and the candour which led him to bear testimony to the high talents and many estimable qualities of the historian, in the funeral sermon which he preached on the death of that great man, did equal honour to Dr Erskine’s head and his heart. The following anecdote has been told of one rupture of the friendship which subsisted in early life between principal Robertson and Dr Erskine. Mr Whitefield, who was sent by the English methodists as a missionary into Scotland, at first formed a connection with the Seceders, the body which had left the established church; but when he refused to confine his ministrations to them, they declared enmity against him, and his character became a controversial topic. Mr Erskine, some time before he obtained the living of Kirkintilloch, appears to have been a great admirer of the character of this celebrated preacher, and to have been strongly impressed with the force of his powerful eloquence and the usefulness and efficacy of his evangelical doctrines. It unfortunately happened, that at the time when the friends and enemies of Mr Whitefield were keenly engaged in discussing his merits, the question as to his character and usefulness was made the subject of debate in a literary society which Robertson and Erskine had formed. Conflicting opinions were expressed, and the debate was conducted with so much zeal and asperity that it occasioned not only the dissolution of the society, but it is said to have led to a temporary interruption of the private friendship and intercourse which subsisted between Erskine and Robertson. There is another anecdote of these two great men, which tells more favourably for Dr Erskine’s moderation and command of temper, and at the same time shows the influence which he had acquired over the Edinburgh mob. During the disturbances in Edinburgh in the years 1778 and 1779, occasioned by the celebrated bill, proposed at that time to be introduced into parliament, for the repeal of the penal statutes against the Roman catholics in Scotland, the populace of Edinburgh assembled in the College court, with the intention of demolishing the house of principal Robertson, who had taken an active part in advocating the abolition of these penal laws; and there seems to be little doubt that the mob would have attempted to carry their threats into execution in defiance of the military, which had been called out, had not Dr Erskine appeared, and by his presence and exhortations, dispersed them.

Dr Erskine’s opinions, both in church and state politics, will be best understood from the following short account of the part which he took on several of the important discussions which divided the country during his life. In the year 1769, on the occasion of the breach with America, he entered into a controversy with Mr Wesley, and published more than one pamphlet, deprecating the contest. He was an enemy to the new constitution given to Canada, by which he considered the catholic religion to be too much favoured. In 1778, when the attempt was made to repeal certain of the penal enactments against the Roman catholics of Great Britain, he testified his apprehensions of the consequences in a correspondence between him and Mr Burke, which was published. And finally, we have already seen, that he took an active and prominent part, in his old age, in support of constitutional principles, when threatened by the French revolution.

Having attained to the 82d year of his age, Dr Erskine was suddenly struck with a mortal disease, and died at his house in Lauriston Lane, Edinburgh, on the 19th of January, 1803, after a few hours’ illness. He had been from his youth of a feeble constitution, and for many years previous to his death, his appearance had been that of one in the last stage of existence; and during many winters he had been unable to perform his sacred duties with regularity; nor did he once preach during the last sixteen months of his life. Before he was entirely incapacitated for public duty, his voice had become too weak to be distinctly heard by his congregation. Still, however, the vivacity of his look and the energy of his manner, bespoke the warmth of his heart and the vigour of his mind. His mental faculties remained unimpaired to the last; and, unaffected by his bodily decay, his memory was as good, his judgment as sound, his imagination as lively, and his inclination for study as strong, as during his most vigorous years, and to the last he was actively engaged in those pursuits which had formed the business and pleasure of his life. Even the week before his death, he had sent notice to his publisher, that he had collected materials for, the 6th number of the periodical pamphlet he was then publishing, entitled, "Religious intelligence from abroad."

In his temper, Dr Erskine was ardent and benevolent, his affections were warm, his attachments lasting; and his piety constant and most sincere. He was remarkable for the simplicity of his manners, and for that genuine humility which is frequently the concomitant and brightest ornament of high talents. In his beneficence, which was great but unostentatious, he religiously observed the Scripture precept in the distribution of his charity and in the performance of his many good and friendly offices. We cannot close this short sketch of Dr Erskine more appropriately than in the graphic words of our great novelist, who, in his Guy Mannering, has presented us, as it were, with a living picture of this eminent divine. "The colleague of Dr Robertson ascended the pulpit. His external appearance was not prepossessing. A remarkably fair complexion, strangely contrasted with a black wig, without a grain of powder; a narrow chest and a stooping posture; hands which, placed like props on either side of the pulpit, seemed necessary rather to support the person than to assist the gesticulation of the preacher,—no gown, not even that of Geneva, a tumbled band, and a gesture which seemed scarcely voluntary, were the first circumstances which struck a stranger. ‘The preacher seems a very ungainly person,’ whispered Mannering to his new friend.

"‘Never fear, he is the son of an excellent Scottish lawyer, he’ll show blood, I’ll warrant him.’

"The learned counsellor predicted truly. A lecture was delivered, fraught with new, striking, and entertaining views of Scripture history - a sermon in which the Calvinism of the Kirk of Scotland was ably supported, yet made the basis of a sound system of practical morals, which should neither shelter the sinner under the cloak of speculative faith or of peculiarity of opinion, nor leave him loose to the waves of unbelief and schism. Something there was of an antiquated turn of argument and metaphor, but it only served to give zest and peculiarity to the style of elocution. The sermon was not read—a scrap of paper, containing the heads of the discourse, was occasionally referred to, and the enunciation, which at first seemed imperfect and embarrassed, became, as the preacher warmed in his progress, animated and distinct: and although the discourse could not be quoted as a correct specimen of pulpit eloquence, yet Mannering had seldom heard so much learning, metaphysical acuteness, and energy of argument brought into the service of christianity. ‘Such,’ he said, going out of the church, ‘must have been the preachers, to whose unfearing minds, and acute though sometimes rudely exercised talents, we owe the reformation.’

"And yet that reverend gentleman,’ said Pleydell, ‘whom I love for his father’s sake and his own, has nothing of the sour or pharisaical pride which has been imputed to some of the early fathers of the Calvinistic kirk of Scotland. His colleague and he differ, and head different parties in the kirk, about particular points of church discipline; but without for a moment losing personal regard or respect for each other, or suffering malignity to interfere in an opposition, steady, constant, and apparently conscientious on both sides.’"

Dr Erskine was married to Christian Mackay, third daughter of George, third lord Ray, by whom he had a family of fourteen children, but of whom only four survived him, David Erskine, Esq. of Carnock, and three daughters.

The works written by Dr Erskine are:-