.....And though a word of God may fall upon a sinful man briefly and be conveyed in nearly 100% purity by a supreme act of grace on the part of God, this is not usually the case. Rather, He permits those who name His Name to grow in the prophetic office degree by degree so that instead of being "taken over", as it were, by the Spirit and acting as mere channels (pardon the New Age term), they become gradually transformed within (akin to sanctification) so that what they speak is always the word of God.
Without exception, all of us begin as babes in the faith after our first salvation event (born again experience) and grow gradually in knowledge, pure feelings and spiritual sanctification. Though devils may have been cast out of our lives, there is still the old Adam Nature ("flesh", "soulish nature") to deal with. It's there all our lives and but either be subordinated through spiritual discipline, or allowed to control us (partially or wholly). Thus a man or woman growing up in the prophetic gift will experience what we call "muddy revelation", that is, the word of God distorted by the fallen Adam-nature. The diagram below illustrates the concept:
You will see how our false belief (theology, for example) acts as a distorting influence on the pure Spirit of God. Wrong motives, a troubled soul, or simply immaturity, may also add to this distoration, to that the final product, whether written or spoken (or both) is a "muddy revelation". Needless to say such revelation can be very dangerous because it can create in the mind of the one who accepts it a false sense of security in all of it because of the truthfulness of the parts of it that have touched his heart, as the Spirit will indeed do.
As the young prophet matures, his theology becoming more alligned to the Bible as a whole, his thinking and feeling refined and purified, so revelation and prophecy will pass through the human lense increasingly unhindered by the Adam-nature. Time and experience are needed to do this. And thus, with greater prophetic clarity, he may correct any tainted or "muddy" revelations he may have had in the past, as Fig.2 below illustrates:
I know that many Christians are uncomfortable with this kind of "process prophecy", if I may coin this term. It is for this reason that God usually calls His prophets from amongst the older and more mature.
In saying these things we must not confuse this "conceptual
revelation" with what is called "verbal plenary
revelation". The latter kind, which is rare, implies that every word is
literally dictated by God and is therefore
100% perfect. This kind of revelation is only possible if you have a
pure language -- and whilst one may obtain
90-95% purity in a modern language like English, for example, you will
never get 100% purity.