The first Christian sermon, preached on the day of Pentecost by the apostle Peter, was preached to the heart. Luke wrote: Now when they heard this, they were stung1 to the heart and said to Peter and the rest of the apostles, “Brothers, what should we do?” (Acts 2:37). That crowd response was the fruit of effective preaching, empowered by the Holy Spirit. But effective, heart-penetrating preaching can also lead to the opposite response: Now when they heard these things, they were pierced through2