David Burrowes, who represents the London constituency of Enfield Southgate, wants Britain to leave the European Union because he believes its power goes against God's word.
He said: "There's a key Christian principle that we see in the Bible: wanting to ensure we don't have too large a state, controlling the lives of communities and families. I feel that the European Union has become too large a state and too large a control over our lives."
David Cameron is currently renegotiating Britain's relationship with the EU, but wants to remain a member if concessions are made to benefit the UK.
A referendum is due to take place before the end of 2017.
If the Prime Minister had opted for collective cabinet responsibility he would have been forced to sack any minister who campaigns for a different result to him.
Commenting on David Cameron's decision to offer freedom on the vote Mr Burrowes said: "It's the right decision. It's probably the most sensible and only decision to make when you competing views within a party that transcend party lines and that transcend the usual rules of the game."
But Liberal Democrat leader Tim Farron - also a prominent Christian - insists it shows a lack of leadership from the Prime Minister.
"The government should take a collective position on this issue, and if ministers disagree with the prime minister they should resign.
"It's absolutely ludicrous. This is about whether or not Britain remains part of the biggest and most important economy on planet earth."
Mr Farron is campaigning for Britain to stay a member of the European Union.
David Burrowes is on the other side of the debate, and says he wants to protect Britain's Christian heritage.
He added: "The rules and laws, the way they've been made up. I think we should be promote those, be proud of those and ensure there's greater control and respect for the ways we do things in Britain, which involves a respect for freedom of faith and religion."