"It was his way of emphasizing the importance of the family, plus all these couples get married under his blessing and that is basically their path to heaven," said Beverley.
Arranged matches are a common practice for members of the Unification Church. Howard Self, a spokesman for organizers of a 1997 mass ceremony at Washington's Robert F. Kennedy Stadium, said after that event that those blessed by Moon could then be legally married later "in their own countries."
Moon has had influence in other ways as well. He grew a massive, diverse business empire -- including holdings in industries such as chemicals, arms manufacturing, mining and pharmaceuticals -- at the same as his church grew, providing him with wealth "that allowed him to ... pursue his religious agenda," said Bromley.
Even after his church's membership in the United States dwindled in recent years, Moon stayed relevant by appearing frequently and sponsoring events for journalists, politicians, scientists and others at which he sometimes offered high-profile individuals large amounts of money to appear, noted Bromley.
He also helped create news publications, universities, religious institutions and other groups. Some such organizations Moon founded stress interfaith dialogue and peace, like the Universal Peace Federation, which advocates "building a world of peace in which everyone can live in freedom, harmony, cooperation and prosperity."
He's also run into trouble with the law, serving a federal prison term in the United States for tax evasion. From 2003 to 2005, the British government prohibited him from traveling to that country, according to a U.S. State Department report.
Still, Moon continued to be regarded highly elsewhere -- including in Washington.
A video from 2004, posted on the website of what was then known as the Interreligious and International Federation for World Peace, showed a ceremony taking place in a U.S. Senate office building attended by Moon and several members of Congress. Speaking Korean, Moon declares himself the messiah and says he'd spoken to the spirits of Nazi leader Adolf Hitler and Soviet leader Joseph Stalin, both of whom he said found strength in his teachings and mended their ways.
Rep. Danny Davis, D-Illinois, is seen reading a poem and wearing white gloves and carrying a crown on a pillow to Moon and his wife. Davis said later he thought it was all part of an interfaith peace ceremony, adding that Moon didn't ask his "permission to call himself the messiah."
Moon was traditionally a strong supporter of Republican politicians, including Richard Nixon and Ronald Reagan, said Eileen Barker, a professor at the London School of Economics and Political Science.
He was also known for being "virulently anti-communist," having been imprisoned in North Korea during the Korean War before being freed by the allies, she said.
Moon softened his hard line on North Korea, though, over time -- even meeting North Korea's founder (and grandfather of its current leader), the late Kim Il Sung, and investing money in the north. He also took pride in talking with Mikhail Gorbachev before the Soviet Union's collapse, calling such meetings a part of the unification movement that connects with the "messiah" and therefore was part of "the restoration," according to Bromley.
In the sermon from August 19 posted online, the Rev. Hyung Jin Moon talked about his father's illness and praised his efforts over the years, as well as stating some of the family's political positions as regards China, Russia and others.
The younger Moon also made a point to thank those who have been praying for his father's health.
"We need to remember, father is not just a normal person," said the Rev. Hyung Jin Moon. "Father's body is not just a normal body."
CNN's Richard Greene, K.J. Kwon and Greg Botelho contributed to this report.