Hear me now and believe me later: "continued" revelation today

I'm working on the last question in the Bibliology section of my NANC Theology exam, "Many Christians today speak of continuing revelation. Relate this concept to inspiration and sufficiency of the Scripture. Relate this concept to the issue of miracles, prophesy and tongues." So, after reading Berkhof, Adams, and Ryrie I decided to consult my $9.99 copy of Grudem's Systematic Theology, which I blogged briefly about last year, so I could verify my understanding of the charismatic/pentecostal view and practice--having been one myself.

What stands out to me both as a former charismatic and a now aspiring Biblical counselor is Grudem's statement, "If prophesy does not contain God's very words, then what is it? In what sense is it from God?". My instinctive question is, "What possible authority or purpose could this sort of 'prophesy' have for Christians and the Church today seeing that God has already 'granted to us everything pertaining to life and Godliness' (2 Peter 1:3)?"

Grudem goes on to build a case that he believes the apostle

"Paul indicates that God could bring something spontaneously to mind so that the person prophesying would report it in his or her own words...uses the word revelation in a broader sense...of communication from God that does not result in written Scripture or words equal to written Scripture in authority...simply referring to something that God may suddenly bring to mind, or something that God may impress on someone's consciousness in such as way that the person has a sense that it is from God..."

To which I ask, Is this not what the Holy Spirit does for all believers--both individually and corporately--without any 'fanfare', or the tag of 'prophesy'?.

Sadly, Grudem goes on to do something that I have found quite common and damaging within the charismatic/pentecostal movement. He relates a story he heard to illustrate and lend credibility to his position--apparently he did not witness this event, which is most often the case among my charismatic/pentecostal brethren, and sadly was my habit as well.

Here's the story Grudem provides (found in chapter 53:A, 5),

"I have heard a report of this happening in a clearly noncharismatic Baptist church in America. A missionary speaker paused in the middle of his message and said something like this: 'I didn't plan to say this, but it seems the Lord is indicating that someone in this church has just walked out on his wife and family. If that is so, let me tell you that God wants you to return to them and learn to follow God's pattern for family life.' The missionary did not know it, but in the unlit balcony sat a man who had entered the church moments before for the first time in his life. The description fitted him exactly, and he made himself known, acknowledged his sin, and began to seek after God."

Grudem further explains,

"In this way, prophesy serves as a 'sign' for believers (1 Cor. 14:22)--it is a clear demonstration that God is definitely at work in their midst, a 'sign' of God's hand of blessing on the congregation."

My follow-up questions are:

1) As we watch the Church begin to encourage, seek, and embrace this new definition and practice of 'prophesy', does it not undermine the Body's commitment to the sufficiency of Scripture? At what point will my 'prophesy' override and/or take precedence over what God has already sufficiently revealed in His Word? How soon till we willingly follow our 'hunches', our 'feelings', our 'impressions', or those of others merely because we desire a 'sign'.

2) How does my seeking after and embracing these 'prophesies' 'build me up in a way that Scripture has not already provided and accomplishes as 2 Timothy 3:16 declares?

3) When will we, as the Body of Christ, stop seeking after 'signs' and find our joy and contentment in Him as we devote our minds and our energy to seeking to know Him and please Him as He has revealed Himself in His Word?