I believe what the enemy has succeeded in doing, with 'his' people in place, was-is to persuade the 'visible' church the written word of God was-is the only means by which God has made available to man for man to understand Him. While this is true, it is only partially so. It should be taken to mean more than what tradition says God purposed the canon to be, i.e., instructions purposed to lead that one "in" the life of God who, by strong desire, seeks to "know" Him: His ways. Reading the scriptures for any other reason renders the Bible a dead book because God cannot be known through the intellect. The scriptures reveal they can only be "understood" by God breathed divine insight [the breath of life of sorts], God having given up in the attempt to make insubordinate man [after the flood, Israel] embrace Him that he would prosper in all he undertook. God desired the results to be that man's [Israel's] progeny would be taught a sustaining knowledge that the world of man [israel] would be changed and subdued for God that man's [Israel's] long awaited redemption would be, in some way, more readily received; Jesus perhaps would not have had to speak in parables??
Jesus having come on the scene, we this read about Him from John the Baptist:
". . . . he shall baptize you with the Holy Ghost and with *fire:" Luke 3:16 (KJV)
*Defining the fire can be as this: "Our God is a consuming fire", meaning the purpose of two manifestations of the Holy Spirit ["in" and "upon" the believer] would be for that reason, i.e., consume any and all in one's life that interferes with His relationship with us.
And then we have this from Jesus:
"I have yet many things to say unto you, but ye cannot bear them now."
His disciples could not bear because as yet they were not indwelt by the Holy Spirit (John 20:22) nor had they received His unction for understanding that would follow several day later on the day of Pentecost.
"Howbeit when he, the Spirit of truth, is *come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come." John 16:12-13 (KJV)
This, by Jesus, intimating what the OT saints never possessed, [which made them very special to God by them submitting theirs lives to God Who remained outside themselves], the enablement to be that which God desired, a "whole people [nation]" after His own Heart.
*Though incomplete, I hope this helps some have a more clear understanding of the reason for Pentecost.
[Good Post andyc]