One of the many things on Ronald Reagan's mind during the height of the Cold War in the 1980s was the nature of Mikhail Gorbachev's religious beliefs. Some recently declassified notes taken during a summit meeting in Moscow in 1988 indicate that Reagan went so far as to attempt to convert Gorbachev to Christianity.
Gorbachev tried to switch the subject. Perhaps the United States and the Soviet Union might open the way for greater cooperation in space, he told the president. But the president wasn't to be diverted. According to the transcript, Reagan told Gorbachev that space was in the direction of heaven, but not as close to heaven as some other things that they had been discussing.
As the meeting ended, Reagan became even more direct and personal. He noted that his own son Ron did not believe in God either. "The President concluded that there was one thing he had long yearned to do for his atheist son. He wanted to serve his son the perfect gourmet dinner, to have him enjoy the meal, and then to ask him if he believed there was a cook."