Our culture doesn't like to think about death. If Ash Wednesday is a reminder that "dust you are and to dust you will return", isn't that morbid? Not at all. Faithfulness to God's Word means that we need to accept the reality of sin and death, and also the love of God for us in Jesus.
The season of Lent begins on Ash Wednesday. In ancient times, people would physically show their repentance by sitting in sackcloth—a rough, burlap-like fabric—and ashes. It was a way to demonstrate to others that you were really sorry for a wrongdoing of some kind.
Living in the world we do today, this is a bit of a foreign concept. If we do anything to show repentance, it should be doing something to make up for what we've done. Doing something like sackcloth and ashes seems so...out of touch. And, it's not really "doing" anything, is it? And, ashes have to do with burning and death. That's morbid. And, since 2018's release of Avengers: Infinity War (SPOILER ALERT), ashes and dust in our culture have become more associated with Thanos' snap of a finger (BIGGER SPOILER ALERT), which can be undone, than with anything remotely spiritual or Biblical.
Why would anyone want to think about death? Isn't it morbid to focus on it? Shouldn't we just enjoy each day for what it is, and put off any thought of what might come later on? Why would we want to spend any time at all reflecting on our own mortality? That's depressing.
For Christians, death isn't a fascination; it's a terrible tragedy. It's the direct result of sin (Romans 5:12). And, it's a reality. Part of being faithful to God's Word is to accept the reality of things, whether they're pleasant to think about or not. As part of a good theology of the cross (more on that later in these days), we have to call a thing what it actually is; we can't ignore the reality of our world, including our mortality.
So Ash Wednesday is a day when Christians around the world accept the reality of their sin. They accept the reality—however painful it is—that death is something that all people will experience (except for those who are still alive when Jesus returns). And they accept the reality that death is a direct result of sin.
Yet that's not all there is to Ash Wednesday. Like so much in the Christian Church, it's not ultimately about us and what we do. Today many Christians will receive from their pastor the sign of the cross on their forehead with ash and oil. This signifies two things: 1. their repentance for their sin, and 2. that they have been marked as ones redeemed by Christ crucified (Romans 5:8-11, Romans 5:15-21). That second bit is super important, because we're not just thinking about our own mortality on this day; we're thinking about how the death of Jesus Christ for sinners put an end to the curse of death forever for us (Galatians 2:19-20).
So yes, as a result of sin, we are dust, and to dust we shall return (Genesis 3:19). But that's not the end of the story. There is so much more! While we wait in repentant faith, we look expectantly for that life that is still to come (John 11:17-27). Dust we are, and to dust we will return, yes. But there is resurrection and new life in Jesus Christ. Both of those are what Ash Wednesday is really all about.