A Kent doctor could face a disciplinary hearing after discussing his Christian faith with a non-Christian patient.
Dr Richard Scott, from Margate, has received a warning from the General Medical Council (GMC) after it received a complaint.
Dr Scott, who has not accepted the complaint, said: "It's very important as a Christian always to do the standard medicine, which I do."
The GMC said it had investigated, but there is no date yet set for a hearing.
The investigation centres around a consultation Dr Scott held in August 2010, with a patient at the Bethesda Medical Centre at the request of the patient's mother.
Dr Scott said that after about 20 minutes he thought the patient may be helped if they had a spiritual discussion.
"He said he was OK with that so we discussed my own faith and where he was with his faith, and I opened up the discussion," Dr Scott said.
Two months after the consultation, Dr Scott received papers telling him the patient's mother had complained to the GMC.
In March, he was told by the GMC that they were going to take on the case and invited a response from Dr Scott.
The complaint stated that Dr Scott had "exploited a vulnerable patient".
Niall Dickson, the chief executive of the GMC, said: "The GMC does not discuss individual cases but our guidance, which all doctors must follow, is clear; doctors should not normally discuss their personal beliefs with patients unless those beliefs are directly relevant to the patient's care.
"They also must not impose their beliefs on patients, or cause distress by the inappropriate or insensitive expression of religious, political or other beliefs or views."
Laura Sandys, Conservative MP for South Thanet, said: "We totally appreciate that medical standards need regulating, but monitoring and then sanctioning doctors on conversations with patients, that do not relate to their medical condition, must be a matter between the individuals and dealt with locally.
"The GMC has over-reacted and needs to put an end to misplaced activism that is putting a respected doctor's profession on the line."
Dr Scott said he would present his case at any disciplinary hearing.