Posted by: Dante536
When he refers to "the Great Journey" he could just be referring to death and nothing else. Many societies and cultures use euphemisms to talk about death (i.e. pass on, go to a better place, etc.) The Covenant could have taken this euphemism literally and thought they actually went somewhere, like when they mistranslated Reclamation for Reclaimer.
That is one of halos remaining mysteries. In one form or another, the great journey is real though.