The report, 'Why Christians Give', was compiled by McConkey Johnston International UK and based on the responses of 2,000 Evangelical Alliance members surveyed last autumn.
It found that tithing was not being actively taught in local churches and that in two out of ten congregations, there was a lack of teaching about stewardship.
"Although some church leaders are emphasising proportional giving in reality we do not know whether they are saying to their congregations 'give what you can afford' or challenging their members to give sacrificially," it states.
The report concludes that churchgoers are being given an "array of mixed messages" from the pulpit about the need to give and that even charities are guilty of handing the task of raising funds to inadequately resourced or inexperienced fundraisers or volunteers.
The report's author, Redina Kolaneci, called on church leaders to see fundraising as part of their calling and improve the quality of their preaching on giving.
"Most Christian leaders seem to believe that they are called to 'do mission' but do not consider that raising the money for this work is part of their remit," she said.
"They tend to sweep money issues under the carpet and fail to preach inspiring sermons on the subject of generosity."
The report found that evangelicals to be generous givers, with nine out of ten donating to their church and to charities in 2009. The average monthly amount donated by evangelical Christians last year was 11.5% of their household income, with 6.5% going to local churches and 5% going to Christian charities.
"This is good news for churches and charities that are prepared to rethink the ways in which they do the asking," said Kolaneci.
The report warned that "a growing number of churches and charities are competing for a limited pool of funds", a situation it said had been made worse by the current recession.
Although surfing the net was one of the top leisure time activities of evangelical donors, few of them were found to be donating online or using social network sites like Facebook or Twitter.
Most Christians, the report noted, are no longer giving habitually but rather evaluating where and how they give, making it more important for charities to understand the dynamics of giving.
Kolaneci said: "Evangelicals are not a homogenous group; they have different priorities, different motivations for giving and different preferred ways of giving," she said.
"Leaders and organisations need to abandon a one-size-fits-all model of fundraising to truly engage with them. For those that are prepared to make the effort, the rewards are still great."
The report was welcomed by Steve Clifford, General Director of the Evangelical Alliance.
He said: "Why Christians Give is a timely report. The church as we know it has changed. We can't take it for granted that the principles of stewardship are widely applied across our diverse church expressions.
"I believe this report is geared to educate and inform Christian leaders on this issue in a positive way. I hope it will inspire us all to act as partners with God to resource His Kingdom."