What is the gospel? The question is based upon the observation that Jesus and his first century followers that wrote the New Testament redefined the phrase word of God to mean either the gospel or, Jesus the living gospel from the book of Acts forward. Assuming that the apostolic writings meant gospel in using the phrase word of God it is very reasonable to try to understand what they meant by that. I further believe that it is reasonable to see the gospel as being the reader’s digest version of the redemptive narrative.
Ephesians 1:4 states that this gospel purpose was birthed before the foundation of the world, and therefore, is the first consideration of God in creation. The wording of Paul in Ephesians 1:3-14 must lead to the conclusion that redemption was the first purpose of creation. There is nothing in the biblical narrative that predates this other than John 1:1-5. John 1:1 states in the beginning (en arche) and assumes that God, and His Word were there prior to Ephesians 1:4. However, Ephesians 1:4 et.al. explains the purpose set forth in creation.
With this in mind, one of the most concise statements of the biblical narrative is Paul’s in 2 Corinthians 5. (2Co 5:18-21 NRSV) All this is from God, who reconciled us to himself through Christ, and has given us the ministry of reconciliation; (19) that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting the message of reconciliation to us. (20) So we are ambassadors for Christ, since God is making his appeal through us; we entreat you on behalf of Christ, be reconciled to God. (21) For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.
The thrust of the gospel narrative that we are responsible to deliver is simply that God was in Christ, reconciling the world to Himself, making the one who knew no sin to be made sin for us, that we in turn might become the righteousness of God in Him. We are to exhort people to be reconciled to God. The redemptive narrative is the ministry of reconciliation. In other words, we are to exhort people to understand they are at peace with God because of Christ (Rom 1:5.)
This peace with God exists so that we might love God with all our heart, soul, and might. The love for God will promote our ability to love our neighbor as ourselves. If we are prompted in our minds to ask about whom our neighbor might be, we are given the parable of the Good Samaritan. Our neighbor may well be someone who hates us.
Likewise, peace with God will be the catalyst for obedience to God. All of the commandments are encapsulated in the idea that we will love our neighbor as we love ourselves. It will only flow from true peace with God which the writer of Hebrews expressed as the Sabbath Rest (Hebrews 4:1-11.)