serving a useful purpose in doing A, doing B
Does

"If art can console us and unite us with others through our shared sensibilities, then it serves a useful purpose in maintaining a social equilibrium, deferring our terror of death even while it reminds us that we will not live forever."

mean

"If art can console us and unite us with others through our shared sensibilities, then it can help to maintain social equilibrium forget our terror of death, even when it itself somehow reminds us that we will not live forever."

Question

serving a useful purpose in doing A, doing B
Does

"If art can console us and unite us with others through our shared sensibilities, then it serves a useful purpose in maintaining a social equilibrium, deferring our terror of death even while it reminds us that we will not live forever."

mean

"If art can console us and unite us with others through our shared sensibilities, then it can help to maintain social equilibrium forget our terror of death, even when it itself somehow reminds us that we will not live forever."

Answer

I'd say that the word order in the first paragraph emphasizes the contrast between not being afraid of death and knowing that it's inevitable. The second could be worded a little more naturally:
"...help to maintain social equilibrium and forget our terror of death, even as it reminds us that we will not live forever."