The Killers frontman was the face of his church's high-profile advertising campaign last year (11) and as a reward for his patronage, religious leaders gave him permission to peruse some of the artefacts housed at their headquarters in Utah.
One item he discovered was a Book of Mormon which had belonged to Presley - and Flowers was fascinated with the handwritten notes made by the Heartbreak Hotel hitmaker.
He tells Q magazine, "Elvis wrote, 'There can be only one King'. He didn't like being called The King because, to him, Jesus Christ was The King. It was so cool that I got to see that."