Rev Rod Thomas, the Chairman of Reform, a conservative evangelical network within the Church of England, said the Prime Minister’s comments were “regrettable”.
He said the suggestion that the church was ‘locking out’ a section in the community was a “misinterpretation” of the church’s position.
“As Christians we advocate and show pastoral care and love to all in the community, following Christ’s command to love our neighbour as ourselves,” said Mr Thomas.
“However the church’s mission is to bring God’s word to God’s world. God designed marriage to be the union of one man and one woman, reflecting the union of Christ as bridegroom and his church his bride. That purpose will never change.
“God is not a person with whom even UK prime ministers can negotiate a more congenial set of commands.
“We utterly deny that by supporting the biblical definition of marriage anyone is being ‘locked out’ from meeting God through Jesus Christ and experiencing his transforming love.”
Mr Cameron hosted a reception at Downing Street on Tuesday for the lesbian, gay, bisexual and transgender community.
He told guests that the Government would be legislating for gay marriage “in this Parliament” and the Coalition was “committed both to changing the law and also working to change the culture”.
Mr Cameron said: “I make that point not only as someone who believes in equality but as someone who believes passionately in marriage.
“If it’s good enough for straight people like me, it’s good enough for everybody and that’s why we should have gay marriage, and we will.”
The Prime Minister’s vow of support for gay marriage comes in spite of strong opposition within his party.
Regarding the church, Mr Cameron said it was a “very complicated and difficult issue” but said he passionately believed “that all institutions need to wake up to the case for equality, and the Church shouldn’t be locking out people who are gay, or bisexual or are transgender from being full members of that Church, because many people with deeply held Christian views are also gay”.
“And just as the Conservative Party, as an institution, made a mistake in locking people out so I think the churches can be in danger of doing the same thing,” he said.
Andrea Minichiello Williams, chief executive of Christian Concern said: “David Cameron’s comments are disingenuous.
“All people are loved by God and welcomed by Him but that does not mean that all behaviour is right or that we can pretend that marriage is something that it is not.
“This is not an issue of equality but of honesty. Commitment is an important aspect of marriage but that is not all there is to it.
“Marriage recognises that male and female are important not incidental – and complement one another.”
The Church of England, the Roman Catholic Church, and the Church of Scotland have all expressed their opposition to the Government’s decision to legalise gay marriage.
The Scottish Government announced this week that it will introduce a Bill to legalise same-sex marriage.
The announcement follows a consultation on the issue that received 77,000 responses. The Scottish Government has refused to reveal how many responses were against the plans.
Announcing the Scottish Government’s decision to push ahead with reform, Deputy First Minister Nicola Sturgeon said: “We are committed to a Scotland that is fair and equal, and that is why we intend to proceed with plans to allow same-sex marriage and religious ceremonies for civil partnerships. We believe this is the right thing to do."
Criticising the move, Ms Williams said it was “astounding” that the Westminster and Edinburgh governments were “bulldozing through” the concerns raised about the proposals.
“This is an ideologically driven agenda that will stop at nothing short of the whole-scale restructuring of society and it is tragic that our political leaders have been so captured by it that they will not listen to the arguments put forward by others,” she said.
“The churches’ responses have not been reactionary or hateful. They have been careful, considered and compassionate but they have also been stark because they have recognised the grave danger. It is shocking that David Cameron, who identifies himself as a Christian, is sweeping them aside.”
Reacting to the controversial comments, The Christian Institute’s Mike Judge said: “The Prime Minister’s sneering remarks show his own intolerance for religious people who disagree with him on gay marriage.
“It is incredibly arrogant of him to tell churches what religious beliefs they should and shouldn’t hold. No wonder huge swathes of churchgoers are suspicious of his motives.”