Common Denominator by Justin Bieber is a song that delves into the themes of love and connection. The song emphasizes the idea that love is a fundamental and universal force that can bring people together, no matter their differences. Bieber sings about finding that one special person who becomes the 'common denominator,' unifying and strengthening the bond between them. The lyrics highlight a sense of passionate devotion and the profound impact that love has on one's life. Key poignant moments in the song include expressions of deep affection and the recognition that this love is what makes everything else in the world make sense.