What does the Bible say about God opening our hearts?

In Acts 16:14, we read about Lydia, a woman whose heart the Lord opened to the message preached by Paul. This act of God is foundational to the Reformed understanding of salvation; it emphasizes that it is the sovereign work of God alone that enables individuals to hear and respond to the gospel. In salvation, God must change our hearts and wills so we can turn to Him in faith and repentance. As it is written in Philippians 1:6, He who began a good work in you will carry it on to completion, showcasing the transformative power of God's opening our hearts.