Re the function of "gärna" in this sentence: As an adverb it can mean "willingly", "readily" or "with pleasure", but this context suggests something different. My Norstedt's has an entry under "gärna" that reads "följden blir gärna den ..." = "the consequence (result) is liable to be ... " Thus, the entire phrase when translated would then read something like, "It is likely that we must wait to meet until we reach the eternal dwellings of peace above where no tears are ever shed." A difficult but plausible scenario in times of yore when travel was much tougher and slower than now and immigrants often didn't have the means to return to the old country even for a visit.