From Mockingbird Blog:
Isaiah’s words are a fitting opening for this season of Advent. In the first nine verses of chapter 1, Isaiah describes the rebellion and iniquity of God’s chosen people; they have not only strayed, they have rejected their God the Lord, the Holy One of Israel, and His commandments (v.4). Isaiah (vv. 10-15) describes the disgust God has over their many sacrifices, vain offerings, feasts. As a result, God turns from His people: “when you spread out your hands, I will hide my eyes from you; even though you make many prayers, I will not listen; your hands are full of blood” (v.15). God, as Judge, has delivered the divine verdict to the people: guilty.
But this is not the final word. Isaiah does not stop there at that word of death. “…though your sins are like scarlet, they shall be as white as snow…” (v18 b). Among great transgressions, God assures His people through Isaiah: it’s not over, this isn’t the final word; there’s one more word to be spoken: the divine promise, the word of life. This word of life, this divine promise is Jesus Christ: the Incarnate God—the promised Suffering Servant (Is. 53)—Redeemer of the world. Jesus is the Word made Flesh (John 1:1-14) who will (by His life, death, resurrection, and ascension) be the perfect propitiation for the sins of the world, and evoke the very repentance commanded by God (vs. 16-17, 19-20; cf. also 1:27-28); through Him sins are atoned for, “though they are like scarlet, they shall be made white as snow” (v.18b).
Let us, during Advent, wait with Isaiah’s audience, knowing our guilt yet brimming with expectant hope at the fulfillment of the divine promise; let us watch with eager eyes for the birth of Jesus, the Word of Life.
Lord, as we enter into this season of Advent, press upon our hearts the gravity of our transgressions And drive us, Lord, to Your unfaltering promise with full and expectant hearts. Prepare our hearts to rejoice in the Word of Life: Your Son, our Saviour, Jesus Christ.