They only are the (true) believers whose hearts feel fear when Allah is mentioned, and when His revelations are recited unto them they increase their faith, and who trust in their Lord;
Times are computed by method; your mosque's timetable governs the adhan. Every text carries its source and grade. Nothing here is a fatwa, a prediction, or a substitute for a doctor: your own scholar decides what is contested, and the tradition itself says the practice is alongside treatment, never instead of it.