"I'm very honored to have you here,'' Stanley told Blagojevich as more than 100 in the audience applauded. "I can't say your last name, but I thank you for coming.''
Stanley's mother married Presley's father in 1960. Stanley, now 56, battled addiction while serving as Presley's "personal aide" but came clean and became a Christian two months after the singer's 1977 death from drug abuse.
Blagojevich, who sat in the first pew with wife Patti and daughter Annie, said he could relate to Stanley's message.
"I can't imagine what it would have been like being governor if I didn't have a faith in something bigger and more important than you to guide you to try to do the right thing for people," he said.