Gospel Doctrine, pg. 479; “JOSEPH SMITH’S NAME WILL NEVER PERISH – God lives, and Jesus is the Christ, the Savior of the world. Joseph Smith is a prophet of God—living, not dead; for his name will never perish.”
Psalm 103:14-15; “For he knoweth our frame; he remembereth that we are dust. 15 As for man, his days are as grass: as a flower of the field, so he flourisheth.”
“Gospel Doctrine” is a compilation of writings and teachings of the prophet Joseph F. Smith. It was originally published in 1919, some 75 years after the death of Joseph Smith, Jr. Joseph Smith is not living and wasn’t living at the time Gospel Doctrine was written.
Saying that he is living implies he is like God.