He studied theology at Bonn (from 1822) under KI Nitzsch and GCF Lucke, held several pastorates, and eventually (1854) settled at Bonn as professor of theology in succession to Isaac August Dorner, becoming also in 1860 counsellor to the consistory.
Lange has been called the poetical theologian par excellence: "It has been said of him that his thoughts succeed each other in such rapid and agitated waves that all calm reflection and all rational distinction become, in a manner, drowned" (F Lichtenberger).
As a dogmatic writer he belonged to the school of Schleiermacher. His Christliche Dogmatics (5 vols., 1849-1852, new edition, 1870) "contains many fruitful and suggestive thoughts, which, however, are hidden under such a mass of bold figures and strange fancies and suffer so much from want of clearness of presentation, that they did not produce any lasting effect" (Otto Pfleiderer).
His other works include Des Leben Jesu (3 vols., 1844-1847), Das rihcsi olische Zeilauier (2 vols, 1853-1854), Grundriss der theologischemm Encyklopädie (1877), Grundriss der christlichen F/hi/s (1878), and Grundriss der Bibelhunde (1881). In 1857 he undertook with other scholars a Theologisch-homiletisches Bibelwerk, to which he contributed commentaries on the first four books of the Pentateuch, Haggai, Zechariah, Malachi, Matthew, Mark, Revelation. The Bibelwerk has been translated, enlarged and revised under the general editorship of Philip Schaff.