The call came from Steve Clifford, General Director of the Evangelical Alliance, Fran Beckett, Chief Executive of the Church Urban Fund, Charles Hoare, International Secretary of CARE, and Dr John Wyatt, University College London professor, at a forum on politics as part of Pentecost Festival.
Ms Beckett said she feared the expenses row had put people off engaging in politics by "reinforcing the disconnect" with politics she said was already happening on a "frightening" scale.
"Far from people wanting to take the risk of going into politics, this may well do the opposite," she said.
Mr Clifford said the scandal had created opportunities for "radical changes" to be made within the parliamentary system, not only in regards to expenses but also in other areas like the use of whips and votes on issues of conscience.
He called for moderation in dealing with the revelations but added that Parliament needed to come up with a "robust response".
Mr Clifford added that excessive claims had become "an almost institutionalised form of corruption where everybody kind of knew this was going on".
"That's where I think every MP has to take responsibility for it," he said. "You can't have the absolute authority that lies within Parliament without taking responsibility for that and tragically 660 MPs failed to take responsibility for this system. I hope this will push us to a place of transparency," he added.
Mr Hoare, meanwhile, said there was an opportunity for Christians to step up and stand in elections, particularly at the local level.
"I hope people would have the courage to put themselves forward to make a positive difference in the leadership of the country," he said.
Ms Beckett echoed his sentiments, saying the church needed to be looking at ways of equipping people to engage in the political process as citizens as well as leaders.
Urging people to vote in the upcoming elections, Mr Clifford said Christians had a responsibility to engage with politics.
"The Gospel has political implications that we can't ignore. We cannot ignore the political landscape that shapes the world and society that we live in," he said.
"My fear is that what has happened over the last few weeks has touched a deep level of cynicism within the British population about the political classes and that's really dangerous.
"We as Christians need to be taking a stand and saying actually now is the time to make sure that we are out on Thursday voting.
"People fought for the right for us to do that. We need to respect that."