If I wanted to go somewhere, I'd need to know several things, first and foremost of which is "where in the world am I?" The same is true with the Gospel... we need to know where we are to begin the journey to the Cross. And that's where the bad news starts... where we are isn't a nice place, and it all comes back to a single event.
It all begins in Genesis. Now, while there are tons of theories about the process of creation - theories that I categorically refuse to get into pointless debates over, the primary thing that seems to be important about the first chapters of Genesis is that it paints a picture of Who God is, what our world is supposed to be like, and what happened to send it down the tubes. God, in these first few chapters, is Creator, Father, Lawgiver, Judge, and Gracious, all in one. Our world is, for lack of a better word, perfect. And us human beings are in a perfect relationship with God and the world around us. We are caretakers and servants of a God that we delight to serve in a world that is beautiful and wonderful beyond measure.
So what happened?
Simply put: we screwed up. Adam and Eve chose Sin over Beauty, and in doing so, ensured that it was Sin that ruled our world. The effect of their Fall was total - it devestated the world around us and ruined our relationship with God, who cannot look upon Sin. It was so complete that it didn't just ruin Adam, Eve, and the critters in the garden - it ruined the entire planet. Earth became a hopeless mess that had been completely seperated from the God that loved it so much (John 3:16).
Worse yet, it condemned us all to a spiritual death (Romans 7:9-13) and ensured that we were absolutely incapable of turning back on our own In fact, Sin helped to ensure that not only are we incapable, but that we are in active rebellion against God... it's not just that we're not God-focused or that we're just slightly off-kilter - we are in active, total, and complete antipathy towards God. We are completely and totally helpless and hopeless on our own.
Fortunately, we're not on our own.