Pretty much.
At the time, athletes had to be "amateur" to compete in the Olympics. The American team was comprised of college athletes who weren't good enough to play in the NHL at a young age. The Soviet team, on the other hand, was essentially the Soviet Red Army team - men against boys. The Soviets wouldn't allow their players to play in the NHL. Every couple of years, the Soviets would send over their team to play a series of games against the NHL All Star team and the Soviets were an equal match for the best that North America could muster.
The closest analogy I can come up with would be watching a football high school All Star team play the Denver Broncos. While they might get lucky for a play or two, in the end it would be a slaughter.
To really see why it was a "miracle", take a look at the movie "Miracle" from about 10 years ago starring Kurt Russell - definitely a "feel good" movie...