Dear Stephen,My father was a missionary doctor (somewhat to his surprise), as he found himself 'qualified' to run a mission hospital, after preparing to emigrate to Africa in the 1950s. As it happens my mother was brought up with the Bible and knew it much better than he, often pointing him to thoughts he could exploit while leading morning prayers, every day at 6am, for Christian members of the hospital staff there, and taking turns at leading 'church' in the hospital, in rotation with others who could. He was dedicated and conscientious and became known locally as 'the doctor who makes you better'. He was on call 13 nights in 14, and had two weeks local holiday a year. He never complained about getting up in the night, because the nursing staff only called him when they knew they had to.If you go to University here (to do medicine) you will be able to evangelise on campus with the UCCF (Universities and Colleges Christian Fellowship (I think it stands for)) programme. You will get invaluable experience at the Christian Union, if not also the opportunity to take part in formal training for various different leadership activities, all overseen by qualified Christian workers. Without doubt, you will see people come to the Lord in their first few weeks of University or, by the end of first year, and you'll get experience answering questions, praying with, sharing the Bible with, many many others who will only come into contact with Christians while they are in this country. Especially if you are open to the Lord to be called to work abroad, the years you spend at Uni could be the last whole years you spend in the UK... Some people never really retire, they just keep moving on to a new field of service, until age or health stops them. There is a Dutch doctor in Africa who retired at the normal age from a standard career in medicine, who then realised there was a need he could meet in another country, and has spent the last 15 years serving the Lord in that (80, now).I think I'm trying to say that if you want to preach, you can preach anyway. The question is more whether that is the only thing God wants you to do with your education. You may not know that there is also a fast track into medicine for people with other previous qualifications; and, there is talk (in the UK) of introducing training for a US style Medical Assistant (don't know if this is what they will be called) who trains as a diagnostician, but, has limited power to order treatment. This is the only bit of advice I'm going to offer - before you decide not to do any sort of University training at all, make sure you have researched your options thoroughly; know what you are turning away from, and make the decision to turn away, very much with the Lord and in His presence. Of course, there would be opposition from people you know, if you don't do what they think is best. I'd say that's less of a longterm problem than leaving yourself a chink which the enemy can exploit year after year, which you will leave for him, if what you choose to do is embarked upon with any doubt whatever. There are many ways the Lord makes His will known, and He will, if you wait until you know it from Him. In the meantime, as the others have said, press on in faith with what you do know is right in general terms. My experience of the Lord's guidance is that He either gives peace for the way forward, or, He takes peace away if you start heading in the wrong direction.The only person who can decide with which He is guiding you, is you. People here will be praying for you. :-)