The Christian wing of the party is celebrating its 25th anniversary.
At an event to mark the occasion at Westminster Central Hall in London, Education Secretary Nicky Morgan read out a message from David Cameron. She said: "Let me send my best wishes to everyone involved in the CCF.
"This silver anniversary is a milestone of which everyone in this party should be proud. Well done. Here's to the next 25 years."
MPs, church leaders and members of the CCF gathered for the celebration and heard from Canon Andrew White, Vicar of Baghdad, who gave the Chair of the group a mosaic cross made by Iraqi refugees.
He went on to encourage those working in politics to not 'take care but take risks'. He also joked that if God was there in person he would be a member of CCF.
The Conservative Christian Fellowship was formed in 1990 by Tim Montgomerie and Conservative MP David Burrowes while they were students at Exeter University.
It now seeks to be the bridge between the Christian world and Conservatives.
The group regularly hosts prayer meetings for Parliament and runs a course to equip Christians for leadership roles.