In Chapter 17 of The Grace and Duty of Being Spiritually Minded, John Owen addresses the severe danger of spiritual decay—a spiritual condition worse than mere slow growth, where a believer's initial love, vigor, and affection for heavenly things gradually wane over time. Owen carefully distinguishes between perceived decays (caused by temporary seasons of severe temptation or natural changes in emotional expression due to aging) and genuine spiritual decline, warning that true backsliding provokes Christ's displeasure, grieves the Holy Spirit, destroys spiritual assurance, and often exposes a superficial initial conversion. Rather than leaving the reader in despair, he offers a compassionate pastoral path toward recovery: urging backsliding Christians to actively recall their former communion with God, lay firm hold of merciful gospel promises, and pursue thorough, unwavering spiritual renewal before their hearts become irreparably hardened.