The characters present in that final church scene are characters both dead and alive in island time, meaning several characters (Kate, Sawyer and Claire included) went on to live a full life beyond the series finale.
The final ever scene of Lost – aptly titled ‘The End’ – is intercut between events on the island and an alternate timeline known as the “flash-sideways – scenes that replace the flashbacks and flashforwards for the entire final season.
The finale of Lost is the most misunderstood of all time.
The plane crash, the smoke monster, the hatch, the island – it was all real.