The Expulsive Power of a Greater Affection

A Biblical Guide to Guarding Your Heart

Ananias and Sapphira were part of the Christian community and witnessed the miraculous growth and unity of the body of Christ in the early church (Acts 5:1-11). Yet, their hearts were captivated not by God’s glory but by worldly desires—namely, the lure of wealth and the approval of others. When they sold a piece of property, they conspired to keep part of the proceeds for themselves while pretending to give the full amount to the apostles. This act of deceit stemmed from a deeper issue: their affections were divided. They wanted the honor of generosity without the sacrifice, showing that their hearts prioritized their own gain over God’s truth.

Their decision had devastating consequences. Confronted by the apostle Peter, Ananias and Sapphira both fell dead as a result of their sin, serving as a sobering reminder to the early church of the seriousness of guarding one’s heart. Their downfall illustrates what happens when affections for worldly things—status, wealth, or approval—replace a genuine love for God.

This story invites us to examine our own hearts. Are we guarding them with the Breastplate of Righteousness, cultivating affections for the things of heaven, or are we leaving them exposed to the allure of the world? This essay explores how a heart captivated by God’s love is the only defense against the destructive power of worldly desires. Drawing on Thomas Chalmers’s concept of “the expulsive power of a greater affection,” we will explore how replacing earthly pursuits with heavenly affections transforms and protects the heart, enabling believers to live in the world but not be of it (John 17:15-18).

The Breastplate of Righteousness: Guarding Our Hearts

As we discussed in our last essay, the Breastplate of Righteousness is both a protective covering and a symbol of holiness. It guards the heart, which Proverbs declares is “the wellspring of life” (Proverbs 4:23). The heart’s affections determine the course of an individual’s actions and character. If the heart is consumed with the things of the world, it becomes vulnerable to sin and separation from God. Therefore, the call to wear the Breastplate of Righteousness is an invitation to guard the seat of our affections against the enticements of the world.