I think it is impossible to preach on this passage without dealing with the question of the consequences of Jesus’ teaching for our own attitude to and the Church’s practice in relation to divorce and remarriage, and this will make it an unusual Sunday. But why does Jesus’ teaching here in Mark appear to be more harsh and absolute than Jesus’ teaching in the parallel in Matt 19? First, we need to recognise that Jesus is not speaking de novo on divorce and remarriage, or using the creation account to rule out all divorce: he is siding with Shammai in taking the stricter, more demanding position.