One of the reasons that you have 8,312 offshoots of Christianity is the bible is vague in its writing and interpretations.
Hundreds of Bible prophecies were fulfilled in ancient times. For example, 700 years in advance, the Bible accurately said that Jesus was to be born in the town of Bethlehem, and that is what happened. (Micah 5:2; Matthew 2:3-9) In addition to many other prophecies about Jesus, the Bible also foretold that he would be born of a virgin and would eventually be betrayed for 30 pieces of silver. Those prophecies also came true. Surely no human could have foretold those things!—Isaiah 7:14; Zechariah 11:12,*13; Matthew 1:22,*23; 27:3-5.
The fall of Babylon. Isaiah and Jeremiah both foretold Babylon’s fall to the Medes and the Persians. Remarkably, Isaiah’s prophecy about this event was recorded some 200 years before Babylon was conquered! The following aspects of prophecy are now matters of historical record: the drying up of the Euphrates River by diverting its waters to an artificial lake (Isaiah 44:27; Jeremiah 50:38); a careless lack of security at Babylon’s river gates (Isaiah 45:1); and the conquest by a ruler named Cyrus.—Isaiah 44:28.
The rise and fall of “the king of Greece.” In a vision, Daniel saw a male goat strike down a ram, breaking its two horns. Then, the goat’s great horn was broken, and four horns came up in its place. (Daniel 8:1-8) To Daniel it was explained: “The ram that you saw possessing the two horns stands for the kings of Media and Persia. And the hairy he-goat stands for the king of Greece; and as for the great horn that was between its eyes, it stands for the first king. And that one having been broken, so that there were four that finally stood up instead of it, there are four kingdoms from his nation that will stand up, but not with his power.” (Daniel 8:20-22) True to this prophecy, some two centuries later, “the king of Greece,” Alexander the Great, overthrew the two-horned Medo-Persian Empire. Alexander died in 323*B.C.E. and was eventually replaced by four of his generals. However, none of these subsequent kingdoms matched the power of Alexander’s empire.
Especially significant is the fact that the Bible foretold when the Messiah would come. God’s Word prophesied: “From the going forth of the word to restore and to rebuild Jerusalem until Messiah the Leader, there will be seven weeks, also sixty two weeks.” (Daniel 9:25) According to the Bible, the word to restore and rebuild the walls of Jerusalem was given in the 20th year of King*Artaxerxes’ reign, which secular history indicates was in the year 455*B.C.E. (Nehemiah 2:1-8) These 69 weeks of years ended 483 years later (7*x*69 = 483), in 29*C.E. That was the very year Jesus was baptized and was anointed with holy spirit, becoming the Messiah, or Christ!
The people in Jesus’ day were expecting the Messiah to appear at that time, as the Christian historian Luke noted. (Luke 3:15) Roman historians Tacitus and Suetonius, Jewish historian Josephus, and Jewish philosopher Philo Judaeus also testified to this state of expectation. Even Abba Hillel Silver, in his book A History of Messianic Speculation in Israel, acknowledges that “the Messiah was expected around the second quarter of the first century*C.E.” This, he said, was because of “the popular chronology of that day,” derived in part from the book of Daniel
Many Bible prophecies are being fulfilled in our time. Here are a few of them:
“Nation will rise against nation [in warfare], and kingdom against kingdom; and there will be great earthquakes, and in one place after another pestilences and food shortages.”—Luke 21:10,*11.
There would be an “increasing of lawlessness.”—Matthew 24:12.
I wouldn't say this is vague, if anything it is so specific, that many people choose to say these were writtn after they happened.