Lifting distressful hands as if to bless. (8)
If there's anyone who will show you compassion and forgive you for your sins, it's Jesus. At least that's what Owen is going for with this image. We don't find out until the end of the poem, but this soldier has been killed by the speaker, and Owen crafts this image to show us his ability to forgive in spite of everything.
"Strange friend," I said, "Here is no cause to mourn." (14)
It's true that speaker number one doesn't know speaker number two yet, but at least now that they're both dead he no longer sees him as an enemy. All he sees is a fellow man who's totally bummed out so he tries to offer him some comfort.
[…] Whatever hope is yours,Was my life also; […] (16–17)
This is Owen doing the work to show that there is no real difference between these so-called "enemies." They both had hopes and dreams for their lives outside of the war, and now they're both suffering together.