See Justin Timberlake, Stephen Colbert Ponder God, Bringing Sexy Back

Pop star, host also perform delightful impromptu performance of the National Anthem

Justin Timberlake joined Stephen Colbert to ponder life's big questions and sing an impromptu harmonized version of the National Anthem.

Stephen Colbert and Justin Timberlake stared into the depths of the cosmos and contemplated the meaning of life, the metaphysics of bringing sexy back and more on The Late Show's "Big Questions With Even Bigger Stars."

Reclining on a big blanket, Timberlake queried Colbert about the origins of God – "Like most stuff, probably a factory in China" – while later the host asked Timberlake if it was possible for the human subconscious to reveal what we are actually thinking about. Timberlake replied, "Of course not, Jimmy Fallon."

Colbert also offered Timberlake a true brain-teaser: Before he brought sexy back, where had it been? The singer explained that his 2006 hit was actually about a neighbor's rabbit, named Sexy, whom he'd been pet sitting. "They were worried I wouldn't return the rabbit, so I wanted to assure them, via song, that I was indeed, bringing sexy back," Timberlake said. "If you listen closely, it's all in the lyrics."

Timberlake also sat down with Colbert for an actual interview during which the singer/actor spoke about passing down his messy and judgmental genes to his son, Silas, and why the church is the best place to start singing. "You know that church is the best place to sing because you can go up there and completely botch anything, and at the end everyone says, 'Amen.'"

Colbert even surprised Timberlake when he convinced the pop star to do an impromptu duet of the National Anthem. The two harmonized the first half of the song in perfect unison, causing an incredulous Timberlake to cut the performance short and declare, "You just blew my mind!"