I love the first stanza of Rumi's On The Day I Die.
On the day I die, when I'm being carried
toward the grave, don't weep. Don't say,
He's gone! He's gone. Death has nothing to do with going away. The sun sets and
the moon sets, but they're not gone.
Death is a coming together. The tomb
looks like a prison, but it's really
release into union. The human seed goes
down in the ground like a bucket into
the well where Joseph is. It grows and
comes up full of some unimagined beauty.
Your mouth closes here, and immediately
opens with a shout of joy there.
----
I like it because for religious people it can be read as a reference to heaven or some kind of afterlife, but also it reminds us that our bodies go back into the earth and provide nourishment for nature, and so we go on in the life that comes next.
For something entirely non-religious, DH's (atheist) best friend read Farewell My Friends by Rabindranath Tagore at DH's funeral, and it was perfect.
Farewell my friends
It was beautiful
As long as it lasted
The journey of my life.
I have no regrets
Whatsoever, said
The pain I’ll leave behind.
Those dear hearts
Who love and care...
And the strings pulling
At the heart and soul...
The strong arms
That held me up
When my own strength
Let me down.
At the turning of my life
I came across
Good friends,
Friends who stood by me
Even when time raced me by.
Farewell, farewell my friends
I smile and
Bid you goodbye.
No, shed no tears
For I need them not
All I need is your smile.
If you feel sad
Do think of me
For that’s what I’ll like
When you live in the hearts
Of those you love
Remember then
You never die.