Gospel is Good news or rather God interacting with us that we maybe a part of His story.
I think we do a big disservice to the Bible and to God reducing the Gospel to an equation or a phrase. The Gospel is basically God's Story. all of the Bible and all of what has happened in History - and our becoming a part of that story.
Now does it make it easy or easier for the unchurched? Well if we use the Christianese vocabulary I think we confuse people.
A Big part of the Gospel is Jesus. God's love. In that also covers the whole character of God - His love, grace, mercy, justice and wrath. So when we talk about the Gospel it isn't just Christology but even some of eschatology, pnematology(sp) other atolgyism if you want to include them.
The Gospel starts at the Beginning of which there is God. And also ends at the end of which there is God. All truth is God's truth and so the Gospel is God's love story and interacting with His people - whether that be Jew or Gentile.
The Gospel is also a pursuit. The start of it to a child might be as simple as John 3:16 or later in life that of leaving the elementary teachings and pursing other disciplines and the continual pursuit of God and all that is Who He is.
Now people like to say this is what makes sense or doesn't. The Gospel to some is that Jesus has these rules: DOs and DON'Ts and we are to follow them. (Legalism)
And then of course if chaos reigns .... then why would we allow Grace to abound?
It is a balance. So what is the Gospel? simple answer: God; and His and our pursuit to get to know one another.
The real question is: If the Gospel is that of what God has done? What do I do as a result?
(Sarcasm button ON)
Package it? Sell it.... Nah, I got it ... let's make the gospel into a tract or into this Roman Road or into a Equation ...better yet let's sell it. I mean package, business like and have our CEO pastors in their CEO building sell the CEO purpose Driven Gospel .... afterall that is what Jesus would do right?
Or let's make the gospel and the Christianese from a noun to an adjective and package that and have Christian homes, Christian music, Christian shirts, Christians bobbleheads, Christian video games, Christian message boards, and of course Christian cars, Christian schools.
Somehow no Wonder people are confused about what the Gospel is or isn't and well people like Jerry Falwell, Fred Phelps, and others with their unfortunate comments now and then don't make it any easier.