There are two basic problems with how the church supposedly carries out its divine role as the administrators of the Gospel. One is that their instruction is almost always a monologue, providing little or no opportunity for the hearer to question and actually understand. That is compounded by their insistence on abiding faith, especially in matters which they cannot explain. The essentiality of faith implies that questioning of what the church teaches is disallowed. Faith cannot be questioning, in effect.
Usefully, the Bible speaks on occasion about the secret things and mystery of God; so that provides ample room for the church to claim that much is unanswerable in the base case; so why would anyone expect them to attempt answers. Just grit your teeth and believe. Maybe you will understand in the sweet hereafter.
Secondly, the church and its theology has developed over the centuries a set of ill defined and therefore confusing doctrinal tenets, generally couched in terminology which further obscures their meaning. Examples are incarnation, sanctification, justification, trinity, discipleship, perfection, intercession, regeneration, conviction, pre-destination, edification, et all. The terminology goes on and on, almost endlessly. Tradition has established definitions to each of these terms, but such explanations are not generally understood nor, in fact, understandable by the majority.
When even life long church members probably couldn't explain the meaning of most of these terms, how do we think that outsiders will understand anything after hearing a 45 minute sermon using such language. No, a message of that type is not designed to effectively communicate to the uninitiated when it hardly does so to the church.
Vague and esoteric language is more often designed to confuse and confound those outside the group and to elevate group members. That is why professional jargons become so popular. They provide a special identity to a select few and elevate those who therefore supposedly understand what is meant. Jargon is never intended to illuminate the masses.