Why do people not understand the gospel today?
People do not understand the gospel today because God has kept its truth hidden, blinding them until He sovereignly opens their eyes. As the mystery was kept secret in God's mind and even the Twelve failed to grasp it, so today many remain blind until His grace reveals it.
Les explains that the gospel was a mystery kept secret in God's mind and not revealed to Old Testament saints; even the Twelve did not understand that Jesus would die and rise, and after the cross they were hopeless, with Peter going fishing. Les says it is the same today: many are kept blind to the truth of the Gospel until God opens their eyes, and then they become intensely responsible because it is His sovereign grace. Abraham also did not understand the gospel; he only had a concept that God would send a Redeemer, and Israel still looks for the Day of Redemption.