A few quotes from the late Rector of the University of Berlin:

“I begin with what is best known and least doubtful, i.e. with that item in the teaching of Jesus which struck His kinsfolk most strongly, and which in fact must have excited the greatest surprise. Jesus is called by His opponents the ‘friend of publicans (tax collectors) and sinners,’ and He frankly accepts the title. It is His commission to go to the lost.

Jesus preaches a God who wants to have dealings with sinful men.

This conception of a God who offers Himself to the sinner is so familiar to present-day Christendom that it is hardly realized how revolutionary after all is such a doctrine – what a contradiction it implies to all religious conceptions recognized elsewhere.

Thus surely Jesus’ conception of God was new. He dealt a blow at everything that earnest ethical thinking about the relation between God and man had established, and everything that the common-sense understanding of mankind down to the present day has held to be the only right standard.”