Does he remember his earth, his birthplace set to torches? (6)
This line definitely plays with the idea of exile. You cannot go back home if your home has been burned down, and so the death of his brother is a form of exile. His brother can never return from heaven.
My father keeps a light on by our bed and readies for our journey. (12-13)
We don't know about you, but this image gives Shmoop the sense that this father wants to be ready to make like a banana and split at a moment's notice. By itself, this quote is not very clear about what's actually going on, but when the word "fugitive" follows close behind, it helps nudge us toward thinking there's at least a suggestion that this family is on the run.
At this hour, what is dead is worried and what is living is fugitive. (20-21)
Wait. Why is our speaker a fugitive? Aside from being falsely accused of murdering his wife (we're looking at you Harrison Ford), what other reasons could a person have for running away? Our speaker doesn't sound like much of a criminal. Maybe he's just fleeing the thoughts and memories of his loved ones so he can finally get a full night's sleep.
[…] his breath of gasoline, airplane, human ash. (25-26)
Gasoline and airplanes call to mind travel, which is a form of escape. And the mention of human ash brings us face-to-face with death again, which is certainly one form of exile from life and the world, although not exactly a good one.
I've had enough of his love that feels like burning and flight and running away. (32-33)
"Running away" says it quite clearly, and "flight," which calls back to the doves mentioned earlier in the poem, also makes us think of fleeing. The fact that our speaker wants nothing to do with God's love, and God's love is connected to flight and running away, makes the complicated nature of escape even more complicated. Why does God's love feel like escape? And if it does, then why does our speaker want to escape it?