I once heard a seminary student refer to himself and his fellow scholars as “God’s sales department.” He believed that the salvation of souls depended on the preacher’s persuasive skills. Considering the quality of average “salesman” (as the student himself lamented), we can be grateful that God doesn’t leave it to the preacher to save sinners, but opens hearts to receive the gospel.
God also must open the human heart before it can receive the saving message and believe. Left to itself, the fallen soul is closed to the gospel:One who heard us was a woman named Lydia, from the city of Thyatira, a seller of purple goods, who was a worshiper of God. The Lord opened her heart to pay attention to what was said by Paul. —Acts 16:14
Because of the radical depravity of man’s fallen nature, the human heart is bolted shut by the twin locks of sin and Satan. In its natural state, no heart is open to God. When God saves His elect, He must open that heart so it can receive the message of salvation. The same word for “opened” is used later in Acts to describe the earthquake that struck Philippi, with the result that “immediately all the doors were opened” (16:26). Those closed and locked prison doors were instantly overpowered by the earthquake and made to open. This is precisely what God did to Lydia’s heart—He instantly threw it open by a spiritual earthquake within her soul. Calvin writes, “Indeed, [believing] does not so stand in man’s own impulse, and consequently even the pious and those who fear God still have need of the especial prompting of the Spirit. Lydia, the seller of purple, feared God, yet her heart had to be opened to receive Paul’s teaching [Acts 16:14] and to profit by it.”
—Steve Lawson, Foundations of Grace (Reformation Trust, 2006), 476–477.