The think tank asked members of the public and charity staff to describe their ideal charity from a list of 20 adjectives. The public rated being trustworthy and honest above all else, but charity employees put passion and independence at the top of their list. Trustworthiness and honesty were ranked 10th and 13th respectively by the sector.
Other discrepancies saw the public cherish helpfulness, accountability and friendliness, while charities emphasised passion, independence and innovation.
"There is a mismatch between what the public wants and what the sector is," said Joe Saxton, founder of nfpSynergy. "The public wants the sector to be like a country GP, but the sector wants to be like an inspiring public figurehead.
"If we want the public to be engaged with the sector, we have to mould ourselves to what the public wants or mould public desires to what we want them to be."
The State of the Voluntary Sector survey found that 92 per cent of charity workers believe the public doesn't understand charities.