He became famous for his investigation of the Messianic Secret theme in the Gospel of Mark.

He suggested that this was a literary and apologetic device by which early Christians could explain away the absence of any clear claim to be the Messiah.

According to Wrede, the solution devised by the author of the Mark Gospel was to imply that Jesus kept his messiahship secret to his inner group of supporters.

He also wrote a crucial study of the Second Epistle to the Thessalonians, which argued for its inauthenticity.

Schweitzer's 1906 book was called The Quest of the Historical Jesus: A Critical Study of Its Progress from Reimarus to Wrede.