User blog comment:Miskos3/Fairy Tail 537: The Power of Life, Review/@comment-4938779-20170527053900/@comment-24053170-20170527072814

He actually was dead, he was only revived thanks to the help of the source of all magic...The One Magic.

Resurrection Magic does not exist in fairy tail in any form(and there is no proof that the R-System would actually ever work).

Basically the only reason Makarov was brought back is because the guild still needed a leader as Mavis departed this world for the next. Otherwise he would have stayed dead.