The Ability to see
"(Beforetime in Israel, when a man went to enquire of God, thus he spake, Come, and let us go to the seer: for he that is now called a Prophet was beforetime called a Seer.) "- 1Sam 9:9 "And as they went up the hill to the city, they found young maidens going out to draw water, and said unto them, Is the seer here? "- 1Sam 9:11
A seer/ prophet was often sought in the Old Testament, for it was through these men/women of God that the people could inquire about God's will, the Holy Spirit not yet been given, Christ not yet been glorified.
Has God stopped speaking since the sacrifice of Jesus on the cross ? So often the verse in revelation is misused trying to say that the spirit of the living God went dumb after the crucifixion."For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book."- Rev 22:18-19 No one seems to have given a moment's thought that this is is direct reference to the book of Revelation only, as the correlation of the whole Bible had not even been done yet, so it could not have been speaking of the compilation of the 66 books of the canon Bible, never mind the Apocrypha or Enoch and Jasher which are heavily referenced in the canon Bible.
That said; what is "seeing" if not the ability to receive the living word spoken by the Holy Spirit? A siritual "perception" if you will. What is the spirit of Jesus Christ? Is it not the spirit of seeing ( prophecy) ? "...worship God: for the testimony of Jesus is the spirit of prophecy."- Rev 19:10
Any "revelation" given by the Holy Spirit will never contradict what has already been given in Scripture; all it can do is confirm, or enhance what is already there.
Are we allowed to speculate, based upon Scripture ? As long as there are no contradictions, yes. The canonized Bible is a foundation upon which to base our belief, otherwise we are as ships cast adrift, without rudder or sail.
Does Scripture give us the ability to "see" things that are not yet evident? Of course. We were told by our Lord that the Holy Spirit would lead us ... into all truth. (Jn 16:13) How is He supposed to do that without giving us dreams, visions ect, all without contradicting what has already been written?
“And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy ("see things"/perceive), and your young men shall see visions, and your old men shall dream dreams:” - Acts 2:17
We are in the time of the end, of this the evidence testifies.