Religion’s in the heart, not in the knees.

Jerrold’s epigram contrasts inward conviction with outward display. By locating religion “in the heart” rather than “in the knees,” he implies that genuine faith is primarily a matter of conscience, compassion, and moral intention—not merely the performance of ritual gestures such as kneeling. The line also carries a satirical edge typical of Jerrold’s wit: it pricks at hypocrisy and social religiosity, where piety can become a public posture. Read more broadly, it argues for sincerity over ceremony and suggests that ethical living is a truer measure of devotion than visible acts of worship alone.