At the end of 1633, being heaVily in debt (Cat. State Papers, Dom. Ser. 1633-34), he returned to England, and in 1634 was ordained priest with a license of non-residence. He was made one of the King's chaplains, and preferred to a small living in Lincolnshire which cost him more for a curate than he received. The same year he attended the Great Frankfort Assembly. The Transylvanian States sent him counsel and advice, and having the credentials of Archbishops Laud and Ussher, Bishops Hall, Morton, and Davenant, and twenty English doctors of divinity, he published his Declarations of English Divines, along with his Latin treatise, Sententice de Pads rationibus Evangelicis. Though he was supported at Frankfort by Roe, he obtained only a general acknowledgment of his services, and the defeat of the Swedes at Nordlingen put an end to the meeting. After a short sojourn in England, he started in July 1635 for the Continent, and laboured for a year in the Netherlands. In June 1636 he went to Sweden, whither he had been invited by Matthia, chaplain to Gustavus Adolphus, and propounded his views to the Lutherans at Stockholm and Upsala. For two years he carried on a voluminous correspondence with Hamburg and the Free Cities. His Swedish negotiations failed. Queen Christina ordered him out of the kingdom in February 1637-38. Although ill in bed, he vowed never to slacken his efforts for religious unity. In 1639 he visited Denmark without success, and afterwards went to Brunswick, Hildersheim, and Zelle, where the reigning Dukes countenanced his views, and a treaty of alliance between all the Brunswick and Liineburg churches was planned with the aid of Calixtus. Early in 1640 he held meetings at Oldenburg and Hainault, and again at Hamburg and the Free Cities, but the joint views of himself and Calixtus were strongly opposed. He now passed through North and South Holland, sent memorials and letters throughout France and Switzerland, and at length arrived in England in 1640-41.

Durie attached himself to the Royalists, and accepted office at the Hague as chaplain and tutor to Mary, Princess of Orange. In 1642-43 he resigned this "uncomfortable position," and became minister to the Merchant Adventurers at Rotterdam. He was summoned to attend the Assembly of divines, and after two years' delay he returned to London, arriving in November 1645. He was one of those who drew up the Westminster Confession and Catechisms.

He remained in England until 1654, continuing his negotiations throughout Europe for Christian unity. In 1645 he preached before Parliament "Israel's Call to Moab out of Babylon," published in 1646. The Parliament granted him a sum of money equivalent to the value of his offices, but he declares he never received a penny. He was married about April 1645 to an Irish lady, an aunt of Lady Ranelagh, who had taken great interest in his Christian work. The lady's estate was worth £400 a year. No rents for a long time were forthcoming, yet she provided a garrison for Parliament " against the rebels " in Ireland. In 1650, Durie was appointed library-keeper, under Whitelocke, of the books, medals, and manuscripts of St. James's, and had lodgings there.

To carry out his second plan of negotiations, Durie left England in April 1654. He now had the approbation of Cromwell and the assistance of the English universities. Labouring through the Low Countries and part of High Germany, he reached Switzerland and presented Cromwell's let^Hto the assembled divines at Aargau, and his scheme was well entertained. He then visited the churches of the reformed cantons, passed on to Frankfort-on-the-Maine, Weimar, Gotha, Brunswick, Hesse, Hanau, Nassau, Hainault, and the Netherlands, and was favourably received at Synods and meetings in all these states from 1654 to 1656-57. He made Amsterdam his headquarters until the latter year. His acceptance of the new ecclesiastical system in England under the Commonwealth brought on him many reproaches. He now limited his ground to unity of opinion on the Apostles' Creed,Ten Commandments, and Lord's Prayer, but being neglected and acrimoniously attacked, chiefly by Lutherans, he was compelled to seek rest in England, whither he returned early in ⁱ656~57. At the Restoration (1660) he endeavoured to renew his work through Lord-Chancellor Hyde and the Duke of Manchester. His letter to the King in vindication of his action under the Commonwealth was unanswered, and Bishop Juxon declined an interview. In 1661-62 he proceeded to Cassel, where the landgrave of Hesse favoured his plans. The landgrave's widow after her husband's death in 1663 continued to favour Durie, and assigned him comfortable quarters at Cassel. From 1663 to 1668 Durie disputed in South Germany, Switzerland, and Alsace. In the latter year the great elector rejected all his plans, and although he continued to travel from his home at Cassel to all parts of Germany and back until 1674, his labour was in vain. " The only fruit," he says, " which I have reaped by all my toils is that I see the miserable condition of Christianity, and that I have no other comfort than the testimony of my conscience."

His life was an incessant round of journeyings, colloquies, correspondence, and publication. He died at Cassel, 26th September 1680. His only child, a daughter, married to Henry Oldenburgh, succeeded to an estate of her father's in the marshes of Kent, valued at £60 a year.—Diet, of Nat. Biog.