What does Acts 2 teach about the fullness of the gospel?

In Acts 2, Peter's sermon encapsulates the fullness of the gospel: the identity of Jesus as both Lord and Christ, His sacrificial death, and His glorious resurrection. This message, empowered by the Holy Spirit, illustrates that salvation is found in Christ alone, who fully satisfied God's justice and opened the way for reconciliation. The apostles preached not a set of doctrines or a plan of salvation, but a person—Jesus Christ. This gospel call extends not just to the Jews present but importantly to all whom the Lord calls. This underscores the Reformed theological position that God's grace in salvation is both personal and extensive, impacting all who believe and receive it.