Mr. Isaacs now went to Jamaica on a short visit to his family, and improved the occasion by giving lectures, which were attended by crowds, in order to stir up an interest in the Holy Land. He had given a very great deal of attention to photography, a difficult pursuit for the amateur in those days, and was the first to introduce it into his native country. On his return to England, he occupied successively posts at Laura Chapel, Bath; in London; at Hanford, in Staffordshire; and at the Priory Church, Malvern.
In 1866, he was appointed by Lord Berners, vicar of Christ Church, Leicester, in his old diocese of Peterborough, where for more than 25 years he laboured in season and out of season, carrying on his ministry on staunch Protestant and evangelical lines, and being surrounded by a large band of fellow-workers, who heartily appreciated his teaching and work. The parish was thoroughly re-organized; numerous useful agencies started; the church restored and its accommodation increased; schools and other buildings erected. Mr. Isaacs was known as "the Jew of Leicester," and continued his great interest in all efforts for the conversion of his brethren to Christianity. He also rendered much and conspicuous voluntary aid to other Societies, notably the Church Missionary Society, the Church Pastoral Aid Society, and the Church Association, as well as to all local institutions and enterprises.
Mr. Isaacs took great interest in elementary education, and was returned at the head of the poll, by a majority of nearly 4,000 votes over the second candidate, at the first School Board election in Leicester. He also greatly interested himself in, and was successful in raising the tone of the Police Force, the members of which most thoroughly enjoyed the winter and summer treats which he arranged for them. Mr. Isaacs was also chaplain of the Leicester gaol, a work in which he took the keenest interest, and where he was the means of leading many a sin-stricken soul to the Saviour of sinners; and reforming the lives of those who had been led astray principally through strong drink. The work at Leicester was thus of a very arduous character. Notwithstanding the poverty of his parish, Mr. Isaacs raised as much as £25,000 for various objects during his incumbency. His whole ministry eloquently testified to the power of a simple and faithfully proclaimed Gospel.
In 1891 Mr. Isaacs was appointed to the incumbency of St. Augustine's, Bath, or, as it had long been known, Portland Chapel, which position he held till 1899. It was a post after his own heart, with its associations and traditions handed down from a long succession of faithful Protestant ministers. For a short time he was in charge of Eaton Chapel, in London. Mr. Isaacs frequently took chaplaincies on the continent, especially in Holland and Germany, and in 1902 he became resident English chaplain to Christ Church, Düsseldorf, and ministered to the congregation there up to the day of his death, on Sunday, November 15, 1903.
His home-call was very sudden, and found him in full work, just as he would have desired. He had no previous illness.
The funeral took place on Thursday morning, November 19, at the beautiful Friedhof cemetery at Düsseldorf, where he rests. Amongst the company present were Mr. Mulvany, the British Consul, with Mrs. and Miss Mulvany, and about 120 other friends, mostly attendants at the Consulate Chapel. The memorial sermons were preached on the following Sunday in the Consulate Chapel by the Rev. T. H. Sparshott. When Mr. Isaacs went there the congregation numbered only about thirteen persons. He soon gathered round him, however, an attached people, upon whose affections he obtained a strong hold, and his ministry was very gratefully welcomed. Not only did he increase the attendance at the Sunday services till an excellent congregation was built up, but on Thursday afternoons, at his own residence, he held Bible readings and social gatherings, which were warmly appreciated by a large number of young men and women. Those who understand the intense loneliness of British residents in a continental city, especially one somewhat off the beaten route of tourists, will readily comprehend how much such kind hospitality and friendly intercourse must have meant to strangers in a strange land.
Mr. Isaacs' travels familiarized him with Palestine, and he wrote "The Dead Sea" (1857); and "A Pictorial Tour in the Holy Land" (1858). He was also the author of the well-known "Biography of the Rev. Henry Aaron Stern, D.D." (1886); and the editor of four volumes of "The Everlasting Nation" (1889-92). Amongst his other publications may be mentioned "Emma Herdman, Missionary Labours in the Empire of Morocco" (1900); "The Fountain of Siena, an Episode in the Life of John Ruskin" (1900); "In the Lord," a series of articles, published in the "English Churchman" (1901); a series of articles entitled "The Tabernacle and the Temple," published in the "Protestant Alliance" magazine (1902); followed by a second series in the same magazine, (1903), entitled "The Protestants of the Bible"; and "The New Vicar" (1903), published posthumously.
Besides his literary gifts, Mr. Isaacs possessed considerable gifts and talents in art and in music, being a keen judge of both. He had some knowledge of colloquial French, Italian, and German, and not long before his death gave a short address in German at a mission hall on "I am the way, the truth and the life," which was listened to with marked attention. He had promised to give a second address on the Wednesday which followed his death.
Mr. Isaacs was a man of keen intellect, marked ability, deeply taught by the Spirit of God, and a faithful servant of Christ during his long ministerial career of fifty-three years. His Jewish descent, his acquaintance with the language and customs of the Jews, his sympathy with them and zeal for their conversion made him a strong and an acceptable advocate in the cause of Jewish missions. He was a Life Member of the L.J.S., and frequently attended the meetings of the Committee, where his long and varied experience, and prudent counsels were fully appreciated.
It will be easily gathered from the above that Mr. Isaacs' life was extremely rich in incident and experience. He was blessed with wonderful strength and health, which he attributed greatly to total abstinence from alcohol and smoking, and enjoyed the friendship of many prominent people, amongst whom may be mentioned Prince Münster.