Christian Hermann Weisse is the first theologian…
March 1838 CE
Christian Hermann Weisse is the first theologian to propose the two-source hypothesis, which is still held by a majority of biblical scholars today.
In the two-source hypothesis (1838), the Gospel of Mark is the first gospel to be written and is one of two sources to the Gospel of Matthew and the Gospel of Luke, the other source being the Q document, a lost collection of Jesus's sayings.