John Lennon was well known as a peace activist, and many of his songs during his solo career after leaving The Beatles called for peace on Earth. Some were a bit more subtle than others, but the simplicity of "Give Peace a Chance" is perhaps what's made it an enduring anthem.
Most of the choruses are primarily filled up of quick lists of somewhat unrelated items. For example, the song starts by saying "Everybody's talking about/Bagism, Shagism, Dragism, Madism, Ragism, Tagism," before launching into the common refrain "All we are saying/Is give peace a chance." Indeed, it is this oft-repeated refrain that most people remember when they think about the song.
The song has an interesting origin. As John Lennon and Yoko Ono began to receive more attention for their political activism, they staged a famous "Bed-In" honeymoon, where they simply sat in bed and allowed reporters in to interview them. In response to a question, Lennon said "All we are saying is give peace a chance," referring to the Vietnam War.
The idea behind the song, while simple, is in line with Ilchi Lee's own teachings and wishes for peace on Earth.
In 2008, Lennon's wife, Yoko Ono, released her own version of the song, although she remixed it to be closer to electronica than the song's original folky roots.