Born in Cincinnati, Ohio, on August 16, 1852, Soden was educated at the University of Tübingen. In 1881 he was appointed as the minister at Dresden-Striesen and in 1887 he became minister of the Jerusalem Church in Berlin. In 1889 he also became a privatdozent, a form of tutor, in the University of Berlin, and four years later was appointed as an extraordinary professor of divinity. He fought for a more presbyterian and democratic constitution in the congregations of the Evangelical State Church of Prussia's older Provinces. His grave is preserved in the Protestant Friedhof II der Jerusalems- und Neuen Kirchengemeinde (Cemetery No. II of the congregations of the Jerusalem's Church and the New Church) in Berlin-Kreuzberg, south of the Hallesches Tor.
Soden introduced a new notation of manuscripts and also developed a new theory of textual history. He believed that in the 4th century there were in existence three recensions of the text of the New Testament, which he distinguished as K, H and I. After establishing the text of I, H and K, Soden reconstructed a hypothetical text, I-H-K, which he believed to have been their ancestor. He then tried to show that this text was known to all the writers of the 2nd and 3rd centuries
His most important book is Die Schriften des neuen Testaments, in ihrer ältesten erreichbaren Textgestalt / hergestellt auf Grund ihrer Textgeschichte (4 vols., Berlin: Glaue, 1902-1910); certainly the most important work on the text of the New Testament which had been published since Westcott and Hort's The New Testament in the Original Greek. Other works include:
He contributed to the 1903 Encyclopaedia Biblica and to the "Hand-Commentar zum Neuen Testament", several editions, started in 1855 by Heinrich Julius Holtzmann and Hans von Soden