An Duanaire (Poems of the Dispossessd) which is one hundred poems in Irish arranged by Sean O Tuama, with verse translated by Thomas Kinsella, gives the last lines somewhat different as follows and that is the version I learned at school.
"O bhás go críoc nach críoc ac athfhás,
I bParthas na ngrás go rabhaimid."

Translation:
"From death to end - not end but growth,
In blessed Paradise may we be."