The gospel or "good news" is set against the backdrop of very bad news. The bad news is that man, as a result of Adam's Fall, has sinned against a Holy God.
"for all have sinned and fall short of the glory of God" Romans 3:23
The consequences of our sin is eternal separation from our Creator.
"For the wages of sin is death . . ." Romans 6:23a
The triune God, Father, Son and Holy Spirit, has provided a remedy to our eternal condemnation by sending the Son, Jesus Christ into this world to live a sinless life, to die an undeserved death and to rise from the dead, as an atonement for the sins of those who would believe in Him.
"but the free gift of God is eternal life in Christ Jesus our Lord." Romans 6:23b
"For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person—though perhaps for a good person one would dare even to die— but God shows his love for us in that while we were still sinners, Christ died for us." Romans 5:6-8
Just as an antidote sitting on a doctor's shelf is capable of healing an ailment, it cannot do so until the antidote is personally taken by the afflicted patient. So too, we who are dead in our trespasses and sins (Ephesians 4:1) must respond in faith to our Lord's remedy in order to be saved from eternal condemnation.
"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. 10 For with the heart one believes and is justified, and with the mouth one confesses and is saved." Romans 10:9-10