Romans 6:23 For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.
Sin entered the world when mankind turned from God in the garden of Eden. Our relationship with Him was severed, how can a holy God be in fellowship with sinful man?
The Good News of the Lord Jesus is, through belief in Him, our relationship with perfect God is restored. Jesus lived a sinless life, and chose to pay for our eternal sins on the cross.
1 Peter 3:18 For Christ also suffered once for sins, the just for the unjust, that He might bring us to God, being put to death in the flesh but made alive by the Spirit,
The free gift of salvation is given to anyone who believes in Jesus, that the Son of God lived, died, and rose again.
Romans 10:9 because, 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.