Whether the Archbishop is referring to this or not, it's important once again to remind ourselves of what the Bible teaches about spiritual warfare. In the West we live in a culture where most people don't believe in evil spirits; if they do, it is at the grassroots of society not in the 'public space'. Christians are often double minded -- we accept the existence of personal spiritual evil in theory, but are sometimes not in practice mindful of it when dealing with illness, depression, ineffective evangelism, problems at work or international crises. Some Christians may have an unhealthy and excessive interest in the demonic, going beyond what the Bible says; other Christians, well, don't believe the Bible. But Anglican liturgy affirms a biblical worldview in this area: candidates for baptism, or their parents and sponsors, are asked to "reject the devil", and to "renounce...evil", and Christ is invoked to deliver the candidate from "powers of darkness" (this is why its important that the new General Synod rejects more attempts to water down this language in our public prayers).

Paul wrote his letter to the Ephesians in a context of very complex beliefs in the spirit realm and common practice of worship of deities, witchcraft and magic. But it's clear from the account of his visit there in Acts 19 that the "principalities and powers" were real. The sons of Sceva (Acts 19:14-15) were not attacked by an imaginary demon any more than the cold violence of IS terrorists cannot be explained only in socio-economic, political or psychological terms.

According to the New Testament, all people are directed away from God by the three-fold influences of the pressures of our environment ('the world'), inner inclination towards selfishness and rebellion (sin, or 'the flesh'), and a supernatural, personal evil power (the devil). In the West, secularism encourages us to focus our resources and technology on dealing with the first of these problems while denying the other two. In animist cultures, the presence of evil is readily acknowledged, and countered by manipulation or appeasement of other powers. In jihadist Islam, evil is externalized in the "other", the unbeliever, those not following the tenets of a pure ideology. The Christian faith alone correctly diagnoses all three problems and provides us with the means of liberation from their power and living life in love and light rather than darkness and fear, or arrogant self-sufficiency. In Ephesians, Paul emphasizes Christ's complete victory and lordship over all supernatural powers, his death for the forgiveness of sin, and his union with the believer, enabling us to live good, counter-cultural lives in the midst of the world rather than being conformed to its values and behaviours. Understanding this is the basis of spiritual warfare.

The church is presented in Ephesians 2 and 3 as a miracle, made up of individual believers saved by grace, consisting of people from different cultures previously at enmity with each other, with the purpose of displaying God's wisdom to the spiritual powers (Eph 3:10). Chapters 4 and 5 give some practical examples of the light-displaying distinctives of Christian life. But because the church is a beacon of God's amazing plan, it becomes a focus of attack. The well-known passage in Eph 6:10-20 shows the Christian life as a war against the powers of evil. Christians are called to recognize the spiritual realities behind daily petty temptations and inconveniences, or massive disasters and crises, and to "stand", to take up a posture of resistance. They do this not with their own abilities, but by being "strong in the Lord and in his mighty power", in union with Christ, while specifically appropriating for themselves the Gospel truths which are symbolized by the soldier's kit in the passage.

The way we do this is through prayer. Spiritual warfare is what Jesus meant when he said of the demon torturing the Syrian boy "this kind can only come out by prayer" (Mark 9:29). People in the grip of evil need more than compassion -- they need deliverance which only Christ can provide. But before we can pray effectively we need to look behind the media reports, the surface analysis from perspectives of the left and the right, and discern the demonic spiritual power behind what even those with no faith are describing as "evil", without whitewashing our own faults. We can allow the shock of what has happened in Paris, and our feelings of sympathy for the people of that city and our own sense of powerlessness, to help us ask spiritual questions and seek understanding as we cling to Christ and pray for his will to be done.

For example, are we praying for the triumph of liberal democracy over fundamentalism? That suggests we see the situation simplistically as goodies v baddies, where all evil resides in "them", the politicians, police and armed forces deal with them, and the rest of us Westerners are let off the hook to continue our own lives, with lazy immorality, self-righteousness and greed unchanged. Nor should we allow vague prayers for peace to be a cover for our desire for a quiet life. Rather we are as Christians all called to be in the battle as intercessors; we should be praying for people to wake up to the reality of evil, the power and goodness of God, for the plans of the wicked to be confounded, Christ to be glorified, for people to repent and turn to him and for his church to grow. We need to pray for wisdom for our leaders who are responsible for maintaining security and social cohesion, who have to make very difficult decisions about refugees and migrants, about war and alliances with dangerous, powerful men.

Most of all we need to pray for Christians on the front line, those still living in the Middle East, as well as those living and working in majority-Muslim communities in Europe. Spiritual warfare involves coming into the throne-room of God on behalf of the persecuted and the suffering, who are bearing the brunt of the fury of evil powers. We can plead that the cup would pass from them, but also that whatever happens, God's will would be done, and that Christ would be glorified.

In the brilliant "Turn back the Battle[1]". Elizabeth Kendal says:

Real prayer is something profoundly different to spiritual fantasy, religious pious duty and desperate wishful thinking...In these darkening days of escalating persecution and insecurity, the church would do well to remember that real prayer is not only a critical and strategic element of the spiritual battle. Real prayer is the highest form of advocacy and God's ordained means of unleashing the forces of heaven (p111).

Terrorist attacks inspire all sorts of emotions and strongly held opinions, some helpful and others not so. To say "let us pray" as a first resort is not a cop-out or an alternative to visible, practical actions, but costly engagement in the spiritual struggle, and perhaps the most transformative and powerful contribution we can make.

The Rev. Andrew Symes is the Executive Editor of Anglican Mainstream