Here's a short explanation of the gospel.
God, the Sovereign Creator of everything, created man in His own image, to reflect His character and moral beauty. We were created to glorify God by loving Him, trusting Him, serving Him, obeying Him, and being thankful to Him.
The first man sinned against God, and by that death and sin reigned through his descendants. He was our federal head, he represented us in the garden. When he fell, we all fell with him. We are born dead in sin, wicked and disobedient before God. We all have sinned and fallen short of the glory of God. We all have turned aside and disobeyed Him and did not give Him the glory that belongs to Him, nor did we give Him thanks. We exchanged God's glory for earthly things and things that are not Him. All of our 'righteousness' and 'good' deeds are as filthy rags before God. They can neither save you, nor help you get salvation.
The wages of sin is death, and we all deserve the punishment of eternal destruction/torment and separation from God forever. Because God who is holy and righteous, must punish sin. But the free gift of God is eternal life in Christ Jesus. For God so loved the world that, while we were yet sinners, He gave His only begotten Son to die for our guilt and sins before God, so that God's wrath and perfect justice against us would fall on Him in our place. And His perfect obedience and righteousness would be imputed on us through faith. He resurrected after three days conquering death, and rose for our justification before God.
In His mercy because of His love, He brought us to life by His Spirit, so that we can respond to this message in faith.
The bible also says "that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation." (Romans 10:9-10 NAS).
If anyone turns from their sins and believes and puts their faith in Christ and what He has done, they are saved. Jesus' perfect righteousness is imputed to the Christian's account, and we are justified by faith in Him. For it is by grace through faith you have been saved, not of yourself, neither by any good work you have done, so that no one may boast.
After being justified by faith, we are adopted as one of His, and the Spirit of God dwells within us. He helps us grow in holiness, faith, righteous conduct, etc; the sanctification of the believer. He also is the seal of our redemption.
