Not satisfied with studying the Bahá’í writings for himself alone, which led him to learn Persian so as to read them in the original language, Esslemont set about writing for the instruction of others. The first nine chapters of his justly celebrated book, “Bahá’u’lláh and the New Era,” which were written during the World War, were submitted to the Beloved Master when peace led to the reopening of communications with Haifa, with the result that Esslemont received an invitation from ‘Abdu’l-Bahá to visit Haifa, which he did in the winter of 1919-20. During this visit the Beloved Master discussed the book with the author, making suggestions for its improvement, and indeed read through and revised some three and a half chapters, which had been translated into Persian for the purpose.

The third chapter relating to Bahá’u’lláh was first published as a separate pamphlet, and it was proposed to issue a new edition on the occasion of the Conference on some living religions within the British Empire which was held in London in the autumn of 1924; on consideration, however, it appeared that a more general pamphlet would be both more appropriate and more useful, and thus “Bahá’u’lláh and His Message” came to be written by Esslemont, who also wrote the small leaflet, “What Is the Baha'i Movement?”

It was not only by his printed works that Esslemont became known to the Bahá’í world, for he was an indefatigable and voluminous correspondent not only in English, but also in Esperanto, of which universal language he was a complete master. Amongst his last labors during his stay at Haifa in 1925 was the revision of the Esperanto translation of the above-mentioned leaflet which had been prepared for the meeting of the Universal Esperanto Congress at Geneva in August of that year. Another work on which he was also engaged towards the close of his earthly career was the translation into German of his large book.

These evidences of Esslemont’s labors in the service of the Cause remain open to all, but of the loving services which he so gladly and selflessly rendered to all with whom he came into personal contact, only they can give full account from the inmost recesses of their hearts; but surely all whom he helped will forever bear in mind the inestimable benefits conferred upon them by his words, and more, perhaps, by his living example of what a true Bahá’í should be, for he was nigh unsurpassed in selflessness, in utter devotion and obedience to the Bahá’í teachings, in love and trustfulness to all his fellows.

No better appreciation of Dr. Esslemont and of his services to the Bahá’í Cause can be given than that contained in the following letter which the Guardian of the Bahá’í Cause wrote after the passing of him who loved the Cause so well and served it so faithfully: