Henry Neufield has this Wesley quote on the site, "Participatory Bible Study Blog":
"Do I understand Greek and Hebrew? Otherwise, how can I undertake, as every Minister does, not only to explain books which are written therein but to defend them against all opponents? Am I not at the mercy of everyone who does understand, or even pretends to understand, the original? For which way can I confute his pretense? Do I understand the language of the Old Testament? critically? at all? Can I read into English one of David’s Psalms, or even the first chapter of Genesis? Do I understand the language of the New Testament? Am I a critical master of it? Have I enough of it even to read into English the first chapter of St. Luke? If not, how many years did I spend at school? How many at the University? And what was I doing all those years? Ought not shame to cover my face?”
John Wesley, “An Address to the Clergy,” in Works X:491.
On the one hand, I agree with Wesley that it would be dubious for those who scorn the learning of biblical languages and indeed much, much more about historical context and the history of interpretation, not to mention the study of theology, to think to speak authoritatively on matters of faith and Christian ethics. True, more urgent are the day to day competencies of ministry. But when situations rise that call for judgments on faith and ethics, those who have scorned expertise in these areas should yield much to those who have.
BUT, there is the prophet to take into consideration too. They are not as prevalent as some are wont to think, but are an important exception.
AND we are not speaking of one theologian or biblical scholar, but of the collective voice of such experts in the church, since one expert will often be idiosyncratic.
FINALLY, Wesley himself did not fully understand the context of Scripture or the inner workings and hermeneutics of how he himself moved from text to doctrine. He suffered under the pre-modern view expressed by Melanchthon that theology was simply the application of grammar to the biblical text. Rather, "context is everything."