Keyword: wilderness.John appeared, baptizing in the wilderness and proclaiming a baptism of repentance for the forgiveness of sins. And all the country of Judea and all Jerusalem were going out to him and were being baptized by him in the river Jordan, confessing their sins. Now John was clothed with camel's hair and wore a leather belt around his waist and ate locusts and wild honey. And he preached, saying, “After me comes he who is mightier than I, the strap of whose sandals I am not worthy to stoop down and untie. I have baptized you with water, but he will baptize you with the Holy Spirit.” (Mark 1:4-8 ESV)
Key concept (1): people were repenting, confessing their sins, aware of their need.
Key question: who can forgive sin?
Answer: God alone.
And to these heartsick sinners this either crazy or holy man, John, says, "Someone is coming who can do for you what no else can do, You lack, above all, the holiness without which none can see God. Well, this Coming One, he will baptize you in what you need."
I mean, really, is that not what is going on here? John message to these repentant ones cannot be more pointedly relevant to their need. It is the second thing we have learned about Jesus from Mark's account. First we learned, in verse 1, that he is the son of God. And here, that he is "coming," and that he will do something extraordinary and really beyond what we can comprehend: "baptize with the Holy Spirit."
Bottom line: this is how Mark begins his "good news," with the news that John is declaring about one who will baptize with the Holy Spirit." It is good news because we lack holiness and need it. And it is good news because there is one who can and will provide it.
Now this is all beautiful and mysterious and very hard to believe, but it is Mark's entry into the whole Gospel. So if we are asking, what is this good news that people are talking about, we would have to say that it has something to do with this coming one, something to do with holiness, and something to do with the Holy Spirit.
When we get to the end of the story, and know much more about how this promise of John's will be fulfilled, we will not want to forget these initial elements. They do get forgotten, very often forgotten, in "presentations" of the gospel. But it's not good news if it is not the solution to our fundamental need. This is why the preaching of John struck such a profound chord in people