I find it hard to think those of the Infinite Hexamon, particularly as they knew about and could translate Mystery, wouldn'tve found the essence of identity. An old debate, but, regardless whether there's an energic substrate supporting matter that consciousness is embedded within, I think the next century, perhaps a little more, will reveal it. (If it hasn't been, already; as, apparently, Tesla inferred, and you, in DEAD LINES, postulated.)
From: Greg Bear
We can always hope! ETERNITY was going for a completely secular solution to heaven/afterlife, based on speculative physics. DEAD LINES takes a different tack, as you note. Folks interested in the former possibility might also look up Frank Tipler's THE PHYSICS OF IMMORTALITY...and Philip Jose Farmer's RIVERWORLD series, which sparked some of my own thoughts almost two decades ago.