What does it mean to believe in your heart?

Believing in your heart, as discussed in Acts 8 and Romans 10, involves a transformation that affects the whole person—intellect, emotions, and will. This belief is not mere acknowledgment of facts about Jesus but a deep trust in His person and work for salvation. Paul states that with the heart, one believes unto righteousness; therefore, this belief involves recognizing one’s inability to produce righteousness and fully relying on the righteousness of Christ. Such faith is foundational, as it aligns with the acknowledgment that Jesus is the Son of God, who alone can save.