Well, if you want to get into SMT, you might try Strange Journey or Nocturne.
SJ has Mara, but is a first person dungeon crawler like SMT 1 and 2.
Nocturne is 3rd person, but doesnt have the Mara we know and love.
Devil Survivor 1 and 2 are turn based tactical RPGs like FE. Neither one has Mara.
Personally, i'd suggest the Persona series, mostly P3 and P4 for getting into the series.
Make sure to play P1 and P2 after you play P3 or P4.
None of the SMT games are direct sequels, with the exception of Raidou Kuzunoha Versus King Abbadon, and P2:eternal punishment being the sequel to Persona 2: Innocent sin