All devout Christians are sinners... except those who don’t need Christ’s sacrifice.
Correction: All devout Christians are repentant sinners...
"For if we sin wilfully after having the knowledge of the truth, there is now left no sacrifice for sins, But a certain dreadful expectation of judgment, and the rage of a fire which shall consume the adversaries" Hebrews 10:26-27
Since Presley was found on the floor of his bathroom by the unmarried woman he was having sex with, Ginger Alden, and the toxicology report showed he had Ethinamate, Methaqualone, codeine, barbiturates, chlorpheniramine, meperidine, morphine and Valium in his system, it doesn't appear that he was embracing the repentance part of being devout. A devout glutton, yes. A devout Christian, apparently not from the evidence.
Presley may have talked the talk but he certainly didn't walk the walk.