The Problem
It is important, I think, to first understand the condition that humanity is in. There is problem that humanity as a whole faces. That problem is sin. Sin ought to be understood as that which "misses the mark" or better understood, moral violations of God's commandments and laws. The first sin committed by mankind was the sin of disobedience. God commanded Adam and Eve not to eat of the fruit of the Tree, and yet Adam and Eve did just that. Therefore, "just as sin entered the world through one man, and death through sin, so also death was passed on to all men, because all sinned." Sin, because of Adam's initial transgression, has now covered the whole mass of humanity from the Fall until the end of human history. This presents a major problem. The problem of sin is that "none are righteous" before God. No one has the ability to please God. Because of sin, we are spiritually dead. What this means is that none can do good, none can stand blameless before God, and so now all are condemned before God. As sinful creatures, we stand condemned before God and subject to His wrath against sin. This should be alarming; because we are subject to God's wrath, we are subject to an eternity of torment and hellfire. What's more, God has promised to judge unrighteousness. We're given explicit imagery in the book of Revelation about God's coming wrath against sin.The Solution
Thankfully, God, in His mercy, has provided a way out of that impending wrath. God sent His Son Jesus Christ, who is the Second Person of the Trinity, to instead bear the wrath of God for those that would instead believe in Christ's divinity and resurrection for the forgiveness of their sins. Christ came to Earth for this expressed purpose. And because Christ's mission is now complete, any that would repent of their sins--their actions that go against the commandments and laws of God, including unbelief--and would place their faith in Christ for the forgiveness of those sins, that same person would find themselves now safely removed from God's wrath and into His mercy and grace.Conclusion
As we've seen, then, the Gospel isn't a means for one to materially prosperous or to be in perfect health. The Gospel isn't merely, "God has a plan for your life". The Gospel is a light in a world that is marred and darkened by a rebellious people. It is the answer to the existential crisis that man faces at the end of human history. It is hope. And it is available to all that hear it, so that if anyone who does hear it believes, that person would be saved.God bless!