"It's millions of commitments from people to the movement that make the big change possible."
He urged churches to "lead by example" and not bend to fit politicians' agendas, but compel the politicians to fit the church's agenda.
"[Martin Luther] King and Ghandi knew you have to change the wind," he said. "But change the wind and it's remarkable how quickly they [politicians] respond. They have an agenda. We can't just fit into their agenda. We have to have an agenda that they respond to. That's what movements have done...that's the big possibility."
Wallis also appealed to Christians not to fall into cynicism but to continue to have hope in change.
"The big choice is the choice between hope and cynicism," he said.
"[Cynics] are against all the bad stuff but you don't think it could ever change. And so your cynicism becomes a buffer against commitment.
"Hope on the other hand isn't a feeling or a personality type. Hope is a choice people make, a decision they make, because of the thing we call faith. Hebrews says faith is the substance of things hoped for...hope means believing in spite of the evidence and then watching the evidence change."
Christians need to invest their time, money, talents and faith into making change happen, Wallis stressed.
"If you don't put everything into it there won't be any movements that change much of anything, but if you do there is no telling what this generation will accomplish."
He concluded: "We've seen a lot of bad religion. Bad religion pulls up the worst stuff. But good religion brings out our best stuff, the compassion of Christ, a hunger for justice...good religion is the answer to bad religion. That time is coming again."
Wallis was joined on the platform by Steve Chalke, the founder of Christian movement Faithworks, which hosted the evening.
He echoed Wallis' sentiments: "Jim is right, politics is broken. Politics isn't working."
Chalke admitted however that as Christians "our theology is broken a lot of the time" and spoke of the need for a move away from "disembodied and spiritual good news" towards a more socially engaged and holistic theology.
"We have got to read our Bibles more closely than we have done and engage more fiercely than we have done," he told the audience, adding, "Faith isn't about an escape and materialism."
Chalke also told Christians that they have nothing to fear from new atheists like Richard Dawkins, author of the God Delusion, saying the fact that Dawkins recently identified himself as a 'cultural Christian' was tantamount to an admission that atheism is morally bankrupt.
"Secular humanism is going to produce a moral desert," he said.
In an age where Christians no longer hold power in society, he continued, Christians "are going to have to demonstrate faith".
"What actually matters is who delivers something down on the ground. That's the challenge to us."
