Ash Wednesday marks the beginning of the Christian season of Lent, a 40-day observance that ends on Palm Sunday, one week before Easter. The 40 days are meant to represent the 40 days Jesus spent fasting and praying in the wilderness before his ministry began. Traditionally, observers of Lent will fast from something—food, TV, etc.—and refocus that attention toward prayer and Bible study. Ever since the Reformation, the Protestant tradition has tended to pass over this season (no pun intended) in an effort to distance themselves from the Catholic tradition. However, in recent years, many Protestants have begun to rediscover the spiritual value of this season, and personally, I don't think there's ever a bad time to dedicate more attention to prayer and to reflecting on the life of Jesus.
The "Ash" aspect of Ash Wednesday is intended to remind us of our fallen mortality and to show us our great need for salvation in Jesus Christ. In essence, the tradition emphasizes what Paul said in 1 Corinthians 15:47 in his explanation of the Resurrection body: " The first man was from the earth, a man of dust; the second man is from heaven." The symbolism of ashes shows us both our fallen nature and our helplessness without Christ Jesus, calling to mind God's curse on Adam in Genesis 3:19 after the fall: " By the sweat of your face you shall eat bread, till you return to the ground, for out of it you were taken; for you are dust, and to dust you shall return."
Robert Alter, in his translation of the Old Testament, renders Genesis 2:7 this way: "Then the Lord God fashioned the human, humus from the soil, and blew into his nostrils the breath of life, and the human became a living creature."1 Most English translations render this word (aphar) as "dust" or occasionally "soil" (CEV, NET, GNT), though the Douay-Rheims Bible (a Catholic translation) renders it "slime." However, Alter's word "humus" depicts something different from the traditional image of God lifting dust into the air. Humus implies mud, almost as if God was shaping man as a potter shapes clay. This fits well with Isaiah's language in Isaiah 64:8: "But now, O LORD, you are our Father; we are the clay, and you are our potter; we are all the work of your hand." Isaiah uses this language elsewhere, and Paul picks up on it in Romans 9.
But there's one more thing to note here. Notice what all of these texts say—they do not say that we are like dust or that we are like clay. Rather, we are dust, we are clay. If this were merely metaphor, it would not pierce us—but this is not merely metaphor, this is what we are. Consider the words of Elisabeth Elliot, a missionary to Ecuador whose husband Jim was killed while attempting to reach the Huaorani people with the gospel (who Elisabeth later lived with and ministered to): "We want to avoid suffering, death, sin, ashes. But we live in a world crushed and broken and torn, a world God Himself visited to redeem."2
Ash Wednesday is a call to remember that we are dust, and that God, who made us from the dust, sent his son to take on our feeble flesh, in order to redeem our broken humanity.
Robert Alter, The Hebrew Bible: A Translation With Commentary
Elisabeth Eliot, A Lamp for My Feet: The Bible's Light for Daily Living