Naturally this is a parody of songs we sing almost every Sunday. Many times our lips say one thing while our hearts if they were revealed would say another. May this never be true of you.
"And the LORD said: 'Because this people draw near with their mouth and honor me with their lips, while their hearts are far from me, and their fear of me is a commandment taught by men, therefore, behold, I will again do wonderful things with this people with wonder upon wonder, and the wisdom of their wise men shall perish, and the discernment of their discerning men shall be hidden.'" (Isaiah 29:13, ESV)
"This people honors me with their lips, but their heart is far from me; in vain do they worship me, teaching as doctrines the commandments of men." (Matthew 15:8, ESV)