Throughout Jesus’s ministry, we are told that He went about preaching the Gospel of the Kingdom ( Matthew 24:14, Mark 1:15, Luke 8:1-2). The prophetic hope of the Old Testament was that the Messiah who would come and establish His Kingdom (Isaiah 9:6). Isaiah prophesied that when the Messiah would come, His kingdom would be established, His rulership would know no ends, and He would rule forevermore. This is happening presently as He rules and reigns while all of His enemies are made his footstool (Acts 2:34–35; Hebrews 1:13; Psalm 110:1-4; 1 Corinthians 15:25; Hebrews 10:11-13).
Jesus also plainly said, when accused of casting out demons by the power of the Devil, that if He cast out demons by the power of the Holy Spirit and not the Devil, then the Kingdom of God has (present tense) come upon you (Matthew 12:27-28, Luke 11:20). Jesus did indeed cast out demons by the power of the Holy Spirit which means His Kingdom had arrived.
When questioned about the Kingdom of God and it’s arrival by the Pharisees, Jesus told them it wouldn’t arrive with signs to be observed which cause one to say, “Look here,” but that the Kingdom was in their midst (Luke 17:20-1).
This is good news because death, sin, Satan and the grave have been defeated. The government powers of the world are subject to Jesus Christ as King of kings and Lord of lords. He has the keys to Death and Hell—all authority in heaven and on earth (Matthew 28:18-20). Christ will one day return and throw all wickedness out of His kingdom, including all of His enemies (Matthew 13:41-3), remove the curse off the creation (Romans 8:22), to rule and reign forever with His people in the New Heavens and New Earth (Revelation 21:1).
It is also good news because the day of salvation is here (2 Corinthians 6:2) and man who is a sinner can be united to Christ—receiving all of the benefits that entails.
The Gospel means “good news” from the Greek word euangelion. This good news was revealed by Jesus Christ himself to the Apostles (Galatians 1:11-12). There is only one gospel message, all others are cursed by God (Galatians 1:6-9, 2 Corinthians 11:1-14). This message is the “power of God unto salvation to all that believe it” (Romans 1:16-17). The call of the Christian church to the world is to repent and believe this Gospel because there is coming a day in which God is going to judge the world in righteousness (Acts 17:31, 2 Timothy 4:1). If someone is not found “in Christ,” they will suffer the eternal consequences of their sins, experiencing the wrath of God (1 Thessalonians 1:10).
The Gospel of Jesus Christ
Man is a sinner (Romans 3:23; 1 John 1:8) and our sin has separated us from our Maker (Isaiah 59:2). In His grace, God entered into His own creation in the person of Jesus Christ (John 1:1-14; Col. 1:19), born of a virgin (Matt. 1:23), and lived a perfect and sinless life, fulfilling all the Law’s demands (2 Cor. 5:21; Matt. 5:17), on a mission by God the Father to save sinners from condemnation (John 3:16-18, 6:37-40). He paid the penalty for sin which is death (Romans 6:23) and bore the sins of His people in His body on a cross (1 Peter 2:24), making propitiation by His blood (Romans 3:25). He died, was buried, and resurrected in the same body He died in on the third day for our justification (1 Cor. 15, Romans 4:25; Luke 24:39). By a living faith (James 2:18) in the Person and Work of Jesus (Romans 10:9-10), God graciously declares a person righteous (Romans 4:5), they are reconciled to their Creator (Romans 5:10-11), given Christ’s righteousness in full (Phil. 3:8-9), sealed with the Holy Spirit (Eph. 1:13), and have peace with God (Romans 5:1). They are born again of the Spirit (1 John 5:1, Titus 3:5), adopted into His family (Eph. 4:5–7), and are granted eternal resurrection life in Jesus Christ (1 John 5:11), set free to do good works that please Him (Eph. 2:10; 1 John 2:3-4). Jesus will physically return one day to judge the living and the dead (1 Peter 4:5; Acts 24:15; John 5:24-5), throwing the wicked out of His Kingdom (Matt. 13:41-3), but His people will be spared from the wrath to come (1 Thess. 1:10) to dwell in union with God forever (Rev. 21:3).