There is a great deal of talk these days about rooting out extremism within our communities—both ‘owned’ communities (whether “British Muslims should do more to combat radical Islamisation among their community” or, “The tabloid press preaches hate to their readership”) and those ‘other’ communities living alongside us (“We should deport xxx”).
There’s an image in the Bible that feels pertinent to this. When the Israelites, rescued from slavery in Egypt, were in the process of colonising the land God had promised to their ancestor Abraham for his descendants, they were warned that if they failed to expel the other populations already settled there, those people would be ‘a thorn in their flesh’—a lifelong irritation, perpetuated down the generations. God’s warning even hints that the Israelites will experience the humbling of being exiled from their homeland.
‘But if you do not drive out the inhabitants of the land from before you, then those whom you let remain shall be as barbs in your eyes and thorns in your sides; they shall trouble you in the land where you are settling. And I will do to you as I thought to do to them.’ Numbers 33:55, 56
‘For if you turn back, and join the survivors of these nations left here among you, and intermarry with them, so that you marry their women and they yours, know assuredly that the Lord your God will not continue to drive out these nations before you; but they shall be a snare and a trap for you, a scourge on your sides, and thorns in your eyes, until you perish from this good land that the Lord your God has given you.’ Joshua 23:12, 13
This begs the question, was God advocating ethnic cleansing? Or—and bearing in mind that no such cleansing took place—was God instructing the Israelites about living with such a thorn?
Millennia later, St Paul, steeped in the Jewish scriptures from birth, picked up on this image of the thorn in the flesh, in a way that might help answer the question.
‘Therefore, to keep me from being too elated, a thorn was given to me in the flesh, a messenger of Satan to torment me, to keep me from being too elated. Three times I appealed to the Lord about this, that it would leave me, but he said to me, “My grace is sufficient for you, for power is made perfect in weakness.”’ 2 Corinthians 12:7-9
Paul uses the term not to refer to a community living alongside him, but to describe a minority element within the Church: those who followed him wherever he carried the good news that the Gentiles were now welcomed into the people of God, telling those converts that they must also be circumcised and follow the Jewish law.
Through a process of struggling with this thorny issue, Paul discovers that it is not simply going to go away. God is not going to sanction their expulsion from the Church. The community of love to which Paul is wholeheartedly committed  will include within it a deeply problematic minority element.
People are complex, and such complexity is inevitable. But this element will serve a purpose, within God’s plan to reconcile all things . They will stop Paul and the wider Christian community from being elated, from complacent self-congratulation. And they will provide opportunity for Paul and those with him to learn what it looks like to operate out of the grace of the Lord Jesus, and not their own strength.
It is easy to point to extremism within other groups, and judge them for it . But if we are honest, there are extremists within every faith and ideology, among theists and atheists, religious and irreligious alike. There always will be. That doesn’t mean we ought to ignore it. But it does mean that we should be neither surprised nor dismayed. Instead, we should be honest about ourselves, and others—their struggles are our struggles; we have much in common—and embrace the grace held out to us, empowering us to be a community of good news.
 See the thirteenth chapter of his earlier surviving letter to this community, for example. And note that the whole Christian community needs to be challenged for their failure to be loving.
 This is a major theme Paul expands on in his second surviving letter to the church in Corinth.
 Of course, the ancient inhabitants of Israel were not extremists. They were civilians. Yet there is the perennial temptation to view difference as a danger to our way of life, the crowd that hides within it dangerous individuals.