Gospel means “good news,” and it is the good news of God’s mighty works in bringing about reconciliation with sinners in and through Jesus Christ and in the power of the Holy Spirit.
Although God made all things good (Genesis 1:31), the goodness of God’s creation was corrupted by the entrance of sin through our first parents, Adam and Eve. Since Adam served as a representative head of all mankind in the covenant relationship that God had established with him, due to Adam’s transgression of that covenant — a breaking of God’s law — all of mankind is now born into an environment of sin and with a nature of sin. We are “by nature children of wrath” (Ephesians 2:3). Our sin calls for God’s judgment, for God is a holy and just God. As the Scripture says, “For you are not a God who delights in wickedness; evil may not dwell with you” (Psalm 5:4) and “God is a righteous judge, and a God who feels indignation every day” (Psalm 7:11).
That’s the bad news which gives understanding to the good news and makes it all the more glorious.
The good news is that God has not left us to our sins and sin’s condemnation. God is also merciful and gracious. God demonstrated his love by sending his Son into the world, “born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons” (Galatians 4:4b-5). This Jesus — the eternal Son of God who took on flesh (John 1:1-3, 14-18) — has accomplished salvation through his perfect life (he was without sin), substitutionary death (he bore the sin, guilt, shame, and punishment of sinners), and powerful resurrection (rose in victory from the grave, defeating sin and death). The Son did this freely and joyfully.
For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many. - Mark 10:45
For our sake he [God the Father] made him [Christ, God the Son] to be sin who knew no sin, so that in him we might become the righteousness of God. - 2 Corinthians 5:21
God raised him up, loosing the pangs of death, because it was not possible for him to be held by it. - Acts 2:24
Though we come into this world under the covenant relationship made with Adam, our first parent, a covenant broken and only promising punishment, God calls us into the covenant relationship of his Son, ratified in his blood on the cross (Romans 5:18-21). You are either in Adam or in Christ. To be in Adam is to be in judgment; to be in Christ is to have the forgiveness of sins and eternal life in loving fellowship with the triune God.
In response, then, God’s word tells us “if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved” (Romans 10:9). Those who repent of their sins and believe in the gospel are adopted as children of God and are kept by the power of the Holy Spirit until the day of glory when all things will be made new and his people, the church, receive their eternal inheritance (Ephesians 1:13-14).
The first Q/A of the Heidelberg Catechism (AD 1563), or the Orthodox Catechism (the Particular Baptist version of the Heidelberg Catechism), is a fitting conclusion to the salvation we have in Christ: