Merrill was born in Anson, Maine. He attended Bob Jones University, where he earned his Bachelor of Arts (1957), Master of Arts in Bible (1960), and PhD in Old Testament interpretation (1963). After moving to New York for his wife to complete her doctorate, Merrill earned an M.A. in Jewish studies at New York University (1970), and his M.Phil. (1976) and Ph.D. (1985) in Middle East languages and culture at Columbia University. He also completed post-doctoral research (1989–1990) at Tyndale House in Cambridge.
