Ash Friday is a time to reflect on creation's fallen nature.
We were created from dust - we will return to dust. Ash Friday allows us the opportunity to think about the broken state we were born into, live in, and will die to. Ash, dust, death, decay; it's in the fabric of our humanity. Everything we do is tainted by it, touched by it. Humanity is broken and stained by the mark of death.
Ash Friday is also a time to reflect on the beauty of Christ.