At least two things I think we can gather about the momentousness of human life from the doctrine of the resurrection of the body:
1. Our individuality will be preserved in eternity. We won't be dissolved into an impersonal divine essence or anything like that; we will be ourselves.
2. Our history matters. What we do and what happens to us and how we respond lasts.
Alice Miller has a theory that everything that happens in a person's life is stored in her body. I don't know whether it's true, but it makes some sense on an intuitive level.
Reading the diary of Sr. Faustina, I notice this:
On one occasion I was reflecting on the Holy Trinity, on the essence of God. I absolutely wanted to know and fathom who God is. … In an instant my spirit was caught up into what seemed to be the next world. I saw an inaccessible light, and in this light what appeared like three sources of light which I could not understand. And out of that light came words in the form of lightning which encircled heaven and earth. Not understanding anything, I was very sad. Suddenly, from this sea of inaccessible light came our dearly beloved Savior, unutterably beautiful with His shining Wounds.
She is overwhelmed by the incomprehensibility of the Trinity, then she zeroes in on Jesus's "shining wounds."
The wounded body resurrected is the point of connection between her soul and God.