The Gospel is the Good News that God’s Son, Jesus Christ, came into the world. He lived a life of sinless perfection to become a perfect sacrifice for sins. He died on a cross to pay the penalty due to others for their sins. He was raised from the dead to prove His sacrifice was acceptable.
The Bible teaches "that Christ died for our sins according to the Scriptures, and that He was buried, and that He was raised on the third day according to the Scriptures" (1 Corinthians 15:3-4). This is the Good News.
God calls us to believe this Gospel. God calls us to recognize our transgressions and misdeeds and confess them to Him. God calls us to place faith in Christ. We must believe His sacrifice paid the penalty for our sins. On the basis of Christ’s sacrifice we ask God to forgive us. On the basis of the power of Christ’s resurrection we ask God to give us the ability to lead a new life.
Is this way of salvation narrow? Jesus says, "The gate is small and the way is narrow that leads to life (Matthew 7:14). The Bible declares, "And there is salvation in [a]no one else; for there is no other name under heaven that has been given among men by which we must be saved" (Acts 4:12).