Being a Christian is "part of who I am" and "people need to get over it", said the new Conservative Senedd leader.
But Darren Millar MS added he was "not a person who likes to impose [his] views on other people".
The Senedd Member for Clwyd West was elected leader of the Welsh Conservatives in the Senedd on 5 December after Andrew RT Davies stood down on 3 December.
He is currently Chief Executive of a Christian charity, the Pocket Book Testament League, and works an average of seven hours a week for the organisation alongside his political work.