I had never heard of this hymn tune until college when we played a handbell arrangement (and where it got the nickname 'PigsGutts").
Recently I included it in worship to find that very few of our (baptist) group knew the hymn (tune or text). I should have guessed that based on the fact that I could only find it in a few select hymnals - and not in any versions of 'The Baptist Hymnal' that I have here (and I have several versions).
The text has been around quite a while (Isaac Watts, 1707) and the PISGAH tune has also been around (American Traditional; Kentucky Harmony, 1816). After you hear it I'm sure you'll agree that it should be up there with other hymns of this topic like "I'll Fly Away", and "I'm Bound for the Pomised Land". I'd even say that it has better lyrics (and music) than either of those.
You can find more info here:
http://www.hymnary.org/text/when_i_can_read_my_title_clear
You can hear the tune (in the exact arrangement that we played back in college) here:
http://www.hymnary.org/node/19928?ref=authority_list
Just click on the play button on the right side next to "Improvisation on "Pisgah""