Good news revealed at the very beginning
The quotation in Eusebius follows
The Elder said this also: Mark, who became Peter’s interpreter, wrote accurately, though not in order, all that he remembered of the things said or done by the Lord. For he had neither heard the Lord nor been one of his followers, but afterwards, as I said, he had followed Peter, who used to compose his discourses with a view to the needs of his hearers, but not as though he were drawing up a connected account of the Lord’s sayings. So Mark made no mistake in thus recording some things just as he remembered them. For he was careful of this one thing, to omit none of the things he had heard and to make no untrue statements therein. (Ecclesiastical History 3.39.15)
Irenaeus (c. A.D. 180) adds his testimony in agreement with the Anti-Marcionite Prologue: “And after their [Peter’s and Paul’s] death, Mark, the disciple and interpreter of Peter, himself also handed down to us in writing the things preached by Peter” (Contra Haereses 3.1.2).
Isaiah 40:3, which looks forward to the coming of another messenger “in the desert” who will go before the people of God in a second Exodus to prepare for the revelation of God’s salvation in Christ.
The Jordan River was also evocative. It was more than simply a river to Jews; it represented the border between the desert and the Promised Land.
When John refers to a more powerful one who is coming, his audience would naturally understand it to refer to God, since God is the Mighty One in the Old Testament, who comes in judgment and pours out the Spirit. This biblical imagery evokes the expectation that God is about to liberate Israel again. But Mark emphasizes that God now acts through his beloved Son.
Like Moses, who gave up his regal status to identify with his people to deliver them, Jesus humbles himself by entering the ranks of sinners and taking his stand with them, just as later he will die for them, isolated and alone. His baptism, therefore, launches him on the servant road of obedience, which ultimately leads to his death
Gundry comments:
His being tempted by none less than Satan, the archdemon, carries an acknowledgment of Jesus’ stature as the very Son of God. The wildness of the beasts with which Jesus is present without harmful consequence bears witness to his being God’s Son, the stronger one of whom John the Baptizer spoke. That even the angels serve Jesus adds a final touch to Mark’s portrayal of him as no less a personage than the Spirit-endued Son of God.
We readers and listeners of this Gospel know far more than the characters in the story. We know that John the Baptizer, the messenger sent before the more powerful one, must be referring to Jesus when he confesses that he is unworthy to stoop down to loosen the thongs of that person’s sandals. We see the heavens rip open at his baptism and the Spirit descending on him, and we hear the voice proclaim that he is God’s beloved Son. This is why we might become exasperated with the disciples who, as the story progresses, sometimes are as thick as a brick. We know more than they do. The coming of the Son of God, who makes a claim on everyone’s life, has made an irreparable breach in the fabric of reality. Perhaps for the first disciples, the light was too bright for their eyes to behold. Perhaps it was not too obscure, but too full of meaning for their minds to grasp. But knowing what we know about Jesus, are we any more faithful, any more discerning, any more willing to give our lives?
The problem is that the way that Jesus prepares for us to go home is not the one we want to travel. It is arduous and paved with suffering, but it is one that we must journey to get home. If the church prepares the way for anything, it is for his return by following in the path he has laid out and in the worldwide proclamation of the gospel