%scripturist%

n. One who is strongly attached to, or versed in, the Scriptures, or who endeavors to regulate his life by them. [ 1913 Webster ]

The Puritan was a Scripturist, -- a Scripturist with all his heart, if as yet with imperfect intelligence . . . he cherished the scheme of looking to the Word of God as his sole and universal directory. Palfrey. [ 1913 Webster ]