Cassel took his degree at Berlin and Licentiatus Theologiæ in due course, and received the faculty for headmaster for all classes of the gymnasium in Latin, Greek, theology, history, geography and German literature. He then, for a time, was on the journalistic staff of the "Constitutionelle Zeitung" in Berlin. Afterwards, in 1850, Cassel went to Erfurt, where he was the editor of the "Erfurter Zeitung" from 1850 to 1856.
His Christian friends, and especially, according to his own statement, his study of the history of Israel, led him to Christianity, which he embraced in 1855, being baptized at Büssleben, a village near Erfurt, on May 28, and receiving the names "Paulus Stephanus." Every year subsequently he was wont to celebrate this "second birthday," as he called it, amidst his friends and congregation.
We now come to the second period of Cassel's life, as a renowned Christian writer, preacher and orator. For a few years Cassel remained in the town, where the great change in his life had taken place, and became custodian of the public library and secretary of the "Erfurt Academy." He was then called to Berlin by the Prime Minister, who entrusted him with the editorship of the official "Deutsche Reform." He resigned this post in six months' time to return to his beloved books and studies at Erfurt.
At this time honours were showered upon him. King Frederick William IV. of Prussia honoured him with the title of "Professor." The University of Erlangen conferred on him the degree of "Licentiatus Theologiæ." Afterwards, in Vienna, Cassel obtained that of "Doctor Theologiæ" (Doctor of Divinity). In 1859 he returned to Berlin and delivered public lectures, which were more and more largely attended and appreciated by both Jews and Gentiles. These lectures made him known throughout the capital and the country.
Dr. Cassel was elected a member of the "Landtag," the Prussian Parliament, in 1866, and became a prominent member of the Conservative party. As this took him too much from his literary work, he soon laid this mandate down.
In 1868, the third and most famous portion of Cassel's life commenced, when the Society appointed him their missionary in Berlin and minister of Christ Church, a stately Gothic building, with over a thousand sittings, erected by the Society in the Wilhelmstrasse, in 1864.
For twenty-three years many children of Israel heard the Gospel from Dr. Cassel's lips both in Berlin and other places of Germany, and indeed of Europe. The good done by means of his sermons and lectures can never be fully estimated; and, in addition to this, numbers of Jews were influenced in a Christian direction by his numerous publications.
It would be impossible for us to follow the indefatigable missionary in his multifarious activities in Berlin and in Germany generally during these busy years; but we may be allowed to quote from a published letter which he addressed in 1887 to English friends, entitled, "Thoughts on the Jewish Mission":
"Invitations came to give lectures in places at a distance. A dear friend of mine shewed me in 1860 a map of Germany, on which he marked all the towns in which I have lectured. Since then I have delivered over a thousand original lectures in Berlin and elsewhere. God's hand has guided me everywhere. My journeys have extended from Amsterdam to Buda-Pesth. I always had an attentive audience, and the poorer people in both large and small towns heard the Word with gladness—nay, even with enthusiasm.
"During the anti-Semitic agitation, such journeys for the purpose of delivering lectures were more extensive. I had then become known through my defence of Gospel charity, even in circles which were not outwardly known as Christian. The meetings which were held at the period resembled more nearly the ideal at which I aimed. A considerable number of persons listened to the lectures, who had completely turned their backs on the Church."