Sometimes the evil in the world simply seems overwhelming. This week, as much as any in recent memory, we seem to have been collectively staggered by the unrelenting darkness around us; being confronted with the realities of the international refugee crisis has forced us to snap out of our usual ambivalence.

We find it hard to take. We ask how on earth this could have happened, while hoping we weren't ignorantly complicit in it.

Mostly though, we can just feel lost, swamped by the size of the problem and the apparent impossibility of a solution that restores the world – and our seared consciences.

It isn't just the current refugee situation which should trouble us, either. Regimes around the world are committing terrible atrocities against their people. The IS terror empire continues to take a terrifying stranglehold on parts of the Middle East. Other countries are wracked with civil war; even an apparently civilised country like America is a simmering cauldron of racial tension and gun violence. Death and suffering are everywhere, and it's getting harder and harder to ignore. The world is sick, poisoned throughout with anger, greed and the thirst for power. Evil is enjoying a renaissance.

It's hard not to feel utterly defeated.

As Christians we're called to be people of hope. We follow a God who is obsessed with restoration, with redemption, with bringing light out of darkness. Our faith is rooted in expectation; in the belief not only that an afterlife will right all wrongs, but that God is already involved in remaking the world for the better.

Which all sounds fantastic. But how does itreally work in practice? When all we can see is a world increasingly broken, how do we hold on to the kind of hope that can propel us to action? I believe the Bible contains some compelling answers.

Believe in what you have not seen

Hebrews 11:1 describes faith as "confidence in what we hope for and assurance about what we do not see". At the heart of the biggest problems we see today are issues of anger and greed, often among powerful people who are apparently immoveable from their positions. Corrupt governments, powerful terrorist organisations and even entrenched economic systems can seem beyond defeat, modern day Jerichos that cannot be breached. We can't see how change is possible, but the Bible suggests we still have to believe it is – and act accordingly. The extraordinary justice campaigner Bryan Stevenson said recently that to work for him "you have to be able to believe in what you have not seen".

Never tire of doing good

In a list of instructions at the end of his letter to the Galatian church, the Apostle Paul includes a wonderful one-liner: "Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up" (6:9). The awful phenomenon of compassion fatigue is perhaps unpleasantly familiar to us. Paul addresses it directly: don't give up, and don't allow yourself to become tired of trying, even when faced with incredible difficulty (as he and the early Church were). It is a discipline to stay hopeful and to keep on fighting for good.

Evil is real, but not victorious

We shouldn't be surprised that evil is on the march. The New Testament is crystal clear that the life we see now is a battleground between good and evil; that God isn't simply in control and moving things around like chess pieces. Paul writes in 2 Corinthians 4 of how the early Church experienced this first hand, yet in each phrase there is always a tension between suffering and hope. "We are hard pressed on every side, but not crushed; perplexed but not in despair; persecuted but not abandoned; struck down but not destroyed" (8-9). These verses should be a great encouragement to anyone struggling with feeling overwhelmed.

The light shines in the darkness

However bad things may seem, the Bible is clear about who wins in the end. At the very beginning of John's gospel (1:5), the writer informs us that "the light shines in the darkness, and the darkness has not overcome it". Jesus wins. Love wins. Goodness wins. That may not change short-term horror, but it can embolden us with long-term perspective.

He will wipe away every tear

Finally, at the very end of the Bible, we get the most extraordinary picture of the God who grieves with us over the state of the world. In his vision of the new heaven and the new earth in Revelation 21, John writes: "'He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away." Right now we are still living in the midst of the "old order of things", but we know not only that these things will one day be no more, but that the God who empowers and guides us as we fight against them is so filled with love and compassion that he promises to dry the tears of the suffering and to make right all that has gone terribly wrong.

These verses can, I believe, be a great help in restoring and encouraging our sense of hope, even in the face of great evil. Simply reading and understanding them however, is by no means enough. They should not simply make us feel better. They should drive us to action and compel us to be the hands and feet of the God who promises that light will overcome darkness in spite of the odds.

This week has knocked many of us to our knees. It's a good place to start from, but it's crucial that we find our way back to our feet. God is calling us to be a people of hope, even in the face of unspeakable evil.

Martin Saunders is a Contributing Editor for Christian Today and the Deputy CEO of Youthscape. You can follow him on Twitter: @martinsaunders