Power of suggestion
Mormon missionaries claim that if a person prays to God the God "will manifest the truth of it unto you by the power of the Holy Spirit" (Moroni 10:4-5). The feeling that it is true during prayer is said to be a "burning in the bosom [chest]". This feeling is more likely to be produced by the power of suggestion because the missionary stated this would happen. Research has shown that suggesting someone will experience a sensation can actually trigger the sensation without the normal stimulus.