Ashes, dust, human, mortal, finite. All of these things describe us. They describe who we are in relation to the world. They describe who we are in relation to God.
This relational human life becomes a series of lens shifts, expanding the frame to keep from being lonely or bored, or narrowing it to keep from feeling anonymous and impotent. 
On Ash Wednesday. In Lent. We open up the frame:
We find insignificance in the relief of absolute significance. We find mortality in relation to eternity. Loneliness in the midst of the crowd of the Redeemed. We find ashes. We find dust. We find the insecurity that the very important matters of our little segment of planet earth are unidentifiable by anyone outside of our little segment of planet earth. And that may be generous. Dust you are. To dust you shall return.
On Ash Wednesday. In Lent. We also narrow the frame:
We find our footing. We find things we can do. We find sins we can repent of. We find the security of a God who shouldn’t care about our sins, but does. We find an eternal and infinite God who finds the petty urgencies of our lives important. To dust you shall return. We find a God who sees in us the building material of a kingdom, not valuable unless formed, yet valuable because it can take form. Dust you are.
Dust you are. To dust you shall return. This is who you are in relation to God. Praise be to God.