My husband and I are addicts of Agatha Christie mysteries! Besides the colourful characters and twisting plots, we love the way the stories overturn traditional expectations. The doctor or the judge – supposedly, respectable pillars of the establishment – often turns out to be the murderer. Meanwhile, the unlikely outsider is the ultimate insider. The grey-haired spinster Miss Marple and the immigrant Hercule Poirot each defy stereotypes associated with old women and foreigners and prove to be cleverer than the police chief inspector. The stories are so familiar that we can forget how far they question and overturn the neat categories that society likes to draw between those labelled as good and upright and those labelled otherwise.

Perhaps, in a similar way, we also forget how much Mark’s Gospel, from beginning to end, powerfully challenges those neat them-and-us divides. The supposedly spiritual people in the story – the characters we might expect to be God’s ‘insiders’ – turn out to be outsiders, lacking in spiritual qualities. The likes of the doctors of the law are accused of hypocrisy and greed, and the high priests are blind to Jesus’ true identity. Jesus’ close followers are not much better: they lack understanding, faith and fidelity. James and John demand high places of honour in the Kingdom; Judas betrays Jesus for money; and, when Jesus is arrested, Peter denies knowing him and all the others run away. Meanwhile, those who might be thought of as ‘outsiders’ turn out to have real spiritual gifts. The humble woman with a flow of blood is congratulated for her faith, and a foreigner like the Syrophoenician woman is praised for her vision.

Today’s Gospel sounds this same theme, continuing to challenge the boundaries between the insiders and the outsiders. As those who follow Jesus, the twelve imagine themselves privileged, they and they only doing God’s work. They associate acting in Jesus’ name with their own status and power, and feel challenged by someone from outside their circle also acting in Jesus’ name! But Jesus doesn’t operate with such a them-and-us view of God’s activity. It’s not about power and status. Jesus looks for what is of God in each one and welcomes it when he finds it, whether or not they belong to a supposed inner circle.

We are only too well aware of living currently in a polarized them-and-us world. As those who belong to the historic Church, we are the children also of multiple polarizations: schisms, persecutions, and them-and-us boundaries. For centuries we have lived comfortably with internal, institutional divisions founded on sexism, racism and wealth. Debates over sexuality threaten our unity. Yet the Gospel story continues to challenge us to look for signs of God at work on every side of the divides.

The challenge goes further still. Whereas at the close of Agatha Christie’s stories the murderer is deftly identified and arrested, the characters in Mark simply can’t be divided into those who are righteous and faithful on the one hand and those who are sinful and unfaithful on the other. Faith and fear, insight and incomprehension, exist mysteriously and ambiguously side by side in every heart. Peter for example both confesses Jesus as the Messiah and refuses to accept that the Son of Man must die. The Roman centurion both ensures Jesus’ death sentence by guarding the cross and at the same time recognizes him as the Son of God.

Seen against this background, today’s Gospel invites us to look inside our own hearts. Following Jesus is not a route to power and a self-righteous mind-set: it leads instead to humble self-examination. Rather than judging or condemning others, we are to seek faithlessness inside our very selves. Using painfully graphic images of amputation, Jesus shocks us in the strongest possible terms into rooting out anything in us that undermines or disparages the faith of others or blinds us to it.

Seeing ourselves so truthfully is not easy, so this Gospel reading drives us necessarily onto our knees asking, beseeching, that God’s light reveal in us all that needs to be transformed. By inviting us first humbly to cut out what is at fault in ourselves, Jesus opens the way to our becoming peace-making disciples whose saltiness is uncompromised. This Gospel challenges us to widen our embrace. It asks us to recognise the presence of God in others, both within and beyond the circles we inhabit. It reminds us that the path of the true disciple is costly. Yes: costly.