In the Holy Gospel for the second Sunday in Advent Saint Luke informs us that the Baptizer fulfills the prediction of Isaiah 40:3 as he becomes God’s heavenly bulldozer. It was thus predicted that the Baptizer would bring down the mountains, fill in the valleys, straighten crooked paths and smooth out the rough places. Certainly the Holy Spirit is not predicting the ultimate landscaper, the greatest dirt-mover who even surpasses our modern earthmovers. Nonetheless the Spirit is informing us of the greatest prophet who, like all other prophets and preachers, is dealing with the landscape of the heart, a landscape that can only be changed by heavenly power.
The proud (e.g. the Pharisees and we) become as mountains of spiritual haughtiness, often thinking of ourselves as being above the need for the Savior. We must be brought low (literally, “humbled”) by the message of God’s law and wrath; thus John preached. The sinners (e.g. the tax-collectors and we) feel so low and beyond salvation that we call to God out of the deep valleys of our sin-sick souls. Thus John preached repentance, proclaiming the Savior, in whom such valleys are filled with the free gift of forgiveness, a forgiveness flowing freely in the fountain of Holy Baptism (both John’s and later Christ’s sacrament).
Either way John is preparing the way of the LORD (“Yahweh” in the prediction of Isaiah). So too our Old Testament lesson predicts that John the Baptist would be the “messenger” whom the LORD would send so “he would prepare the way before Me (Yahweh, the first person speaker in Malachi 3:1).” Yes Jesus is the LORD, He is Yahweh, for only the LORD God could bestow upon John the Baptist such awesome bulldozer words.
But the bulldozer words of John are not merely words. They are words that have backing and they are words through which the Holy Spirit changes hearts to be prepared for the LORD. The words of repentance preached by John—and indeed by all preachers of God’s Word from the beginning to the end of time—are words that are backed by the cross and the empty tomb of the LORD—the eternal Son of God. He “was delivered up for our trespasses and raised for our justification.” (Rom. 4:25) Indeed such a haughty mountain as the Pharisee Saul, and such a deep valley as the tax-collector Matthew, find their hearts so miraculously transformed by the powerful word of God our Savior, that in the love and forgiveness of Christ, the Holy Spirit with the Father and the Son make their abode with such forgiven sinners (John 14:16,17, 23). Truly the Gospel is the power of God unto salvation (Rom. 1:16), preparing and transforming the hearts of mankind unto salvation.