But above all, those who knew him spoke of his human qualities.
"What always struck me about him was that he was just the epitome of kindness and gentility and warmth and humor," said Salt Lake City Mayor Ralph Becker. "He was the kind of person who we would all want to aspire to be as a human being."
Utah Gov. Jon Huntsman issued a statement saying Hinckley's "leadership in humanitarian efforts around the world was matched only by his efforts in his own beloved state and community as a committed citizen.
"He has stood as a remarkable example of selflessness, charity and humility and he will be greatly missed by all."
The governor authorized state and U.S. flags to be lowered in Hinckley's honor and flown at half-staff on all state-owned facilities until sunset on the day of his interment.
Mitt Romney, a Mormon and candidate for the Republican presidential nomination, added: "I was saddened to learn of the death of Gordon B. Hinckley. Ann and I respect him as a man of great faith and character. Like all people who knew him, we were deeply touched by his humility, his sense of humor and by the way he inspired so many people around the world. We will miss his leadership."
Nevada Senator Harry Reid added: "President Hinckley led a remarkable life. His faith and leadership have inspired countless lives throughout the world. He leaves a deeply rooted legacy on our religion through his teachings and his lifetime of service to the Church. My thoughts and prayers are with his family."
News of Hinckley's death sparked spontaneous expressions of mourning at Temple Square and on the campus of Brigham Young University.
Several hundred people gathered east of Salt Lake City's Temple Square to sing hymns, while families and groups huddled together holding lighted candles. Late Sunday night, the crowd knelt in silent prayer.
"He was the prophet for half of my life. He was so humble, yet so strong. He taught people how to do the best you can and move forward with your faith," said Rachel Cox of Ogden.
More than 200 BYU students braved the cold to sing hymns on the Provo campus.
Freshman Jeff Summers saw it as a sad moment, but one that contains lessons about life. "He's going home and someone is going to step in to fill his place," Summers said.
Utah high school students were spreading the word via Internet and cell-phone text messages Sunday night. The messages said that today will be "dress up for President Hinckley day."
Sen. Orrin Hatch said in a statement that Hinckley's life "was a true testament of service, and he had an abiding love for others.
"His wit, wisdom, and exemplary leadership will be missed by not only members of our faith, but by people of all faiths throughout the world."
Hatch added: "He was an articulate leader and defender of our Christian principles; and had a unique gift and way about him to communicate with people from all walks of life, and all religious persuasions. I truly loved this wonderful man."
Former Salt Lake City Mayor Rocky Anderson called Hinckley "one of those rare people who exuded such tremendous warmth, wit and goodwill, with people of all kinds.
"In my dealings with President Hinckley, he was always incredibly gracious and strove in every way to bring people together while respecting their differences."
Anderson said he always walked away from his interactions with Hinckley "feeling uplifted and even energized. He had enormous energy and drive, even at a very advanced age and seemed remarkably sharp, always."
Sen. Bob Bennett said in a statement he had known Hinckley since his early 20s and that "the thing that has impressed me the most about him has been his humility. He always viewed his assignments, no matter how great or small, as opportunities to serve rather than positions of prominence.
"He stayed fully engaged and completely up to date right to the end and his legacy will be remembered long after all the rest of us are gone."
Bishop John Wester, of the Catholic Diocese of Utah, called Hinckley "a real man of bridge-building. A real man of God."
Wester said Hinckley's feelings of caring for people extended beyond the LDS Church.
"He wasn't exclusive, he wasn't insulated," Wester said. "He showed a genuine interest in me personally, and a genuine interest in our church."
Calvary Baptist Church Pastor France Davis, said: "I'm deeply sorry and share the grief and would express to his family our care and concern.
"He was a good friend. He helped get a lot of things done, including passage of the Martin Luther King Holiday bill [in the Utah State Legislature]."
University of Utah President Michael K. Young said of Hinckley: "Citizens of all nations will miss his great faith and boundless energy, his vision and spiritual resonance, and his compassion and gentle good humor. Truly the world is poorer today because of his passing."
Young noted that Hinckley was a 1932 graduate of the U., and also delivered the 1998 commencement address, in which Hinckley urged graduates to dedicate a part of their time to "those in distress and need . . ."
* THOMAS BURR, NATHAN GONZALEZ, AND DONALD W. MEYERS contributed to this report.