There are many violent points in history, at which we look back, and wish that the people at the time had done something different. Had done more, to stop an incredible evil being carried out.

We have a choice today, individually and as a community, of how to react to some truly demonic atrocities in the world. To respond to an organisation that celebrated as they deliberately burned a man to death, and a community that cheered as they watched this hideous torture being played on video screens. To react to an Islamic 'State' in Iraq and Syria, that seeks to expand its borders, where a UN committee says that children are being used as suicide bombers, buried alive, crucified and sold as sex slaves, partially based on reports from Amnesty International. It's not much better in Nigeria, where people are being murdered if they don't convert. And these groups want to expand – to violently take over more land to impose their fascist ideology onto it.

What will we do about it? Will we turn the TV off when the horror becomes too much? Will we go on in our comfortable lives, distracted by TV, iPhones and earning our crust – while such outrages are taking place? Will we argue for gay rights, or Christian rights, or women's rights, in our own, relatively strife-free country – while gay people are thrown off buildings and stoned to death, Christians are crucified, and girls are bought and sold? 

Opinions on exactly how we should react as a Christian community, or as a country, depend on politics and theology. Some are pacifist, some are not. Some think the West bears responsibility for the conditions that led to the creation of ISIS, some don't.

Whatever your view, it must be time to take action. Whether or not we are pacifists, we can still pray, long and hard: for those who are suffering, for a change of heart in the ISIS sadists, for the intelligence services who are trying to find out what's going on. Every time we read or hear about the situation, we can offer up a prayer to God. We need to urgently pester our MPs to treat this as a priority. We need to pray for the westerners and the local militias who are fighting ISIS – at the very least for their protection from the outrageous war crimes of ISIS, and that they themselves keep to acceptable wartime conduct. There is also a petition asking the UN to take action that we can sign. 

There are so many causes that need our support in this dying, troubled and desperate world. But surely expansionist, sadistic, genocidal, child-abusing governing authorities are an absolute priority for those who care about social justice?

There are individual stories of great bravery in World War II: The ordinary soldiers who lost their lives: Individuals such as Corrie ten Boom, who risked lives to save Jews and suffered in concentration camps as a result; The church leaders who successfully fought the outrageous Nazi T4 programme that was murdering people with mental difficulties. Would you have done this? True, it's difficult when the horrors are happening elsewhere – and even if they were on our doorstep, challenging them would be incredibly dangerous. But there are people living in our own country who are sympathetic to ISIS – one in ten young people in our country had 'warm feelings' towards the organisation, according to one poll last October and some are going to join it. Do we know these people, these communities? Do we pray for them?

There's a well-known apocryphal story of a German church during the Holocaust, situated within hearing distance of the cries of people being taken away on trains every Sunday. They did nothing, and instead, tried to sing their hymns louder, to drown out the sound. "God forgive all of us who called ourselves Christians, yet did nothing to intervene", said a worshipper, according to one version of the story.

Stephen Fry was all over the media for his anger towards God for all the suffering in the world. I suspect that when we get to the pearly gates, if we dare to shake our fist at God and criticise him for all the suffering – he will show us all the billions of actions he did to steer people away from their bad choices. And then the question will come right back at us: "And what did YOU do?"