My guess: Partiality reflects testimonial communication. Detail and Sober mood asks for full acceptance but does not communicate exhaustively. This text is to serve as foundation of all other beliefs, and is to be accepted as true testimony. Belief in testimony relies on recognition that the believer isn’t able to make final critical judgment from privileged epistemic status. Knowledge of believer is true yet partial. Just as Adam and Eve, this knowledge is to be subject to God and yet is given much evidence for trusting in it, and much liberty within its constraints. The appeal to submit to and follow God does reject our reason, but gives every reason available. Yet the request to submit is not communicated in terms that assume our epistemological independence or authority.