There are many passages in the Bible that suggest that knowledge has been kept hidden from humanity.
Isaiah 56:1 Thus saith the LORD, Keep ye judgment, and do justice: for my salvation is near to come, and my righteousness to be revealed.
Matthew 10:26 Fear them not therefore: for there is nothing covered, that shall not be revealed; and hid, that shall not be known.
Romans 16:25 Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,
The Bible is very enigmatic and this by itself suggests that some things have been kept secret, but we are assured that everything will be revealed. Christians tend to believe that all things were revealed by Christ during or in the period that followed His first coming.
1 Corinthians 2:7 But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory:
Colossians 1:26 Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
Ephesians 3:5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
Many things were revealed by Christ, but Jesus spoke in parables, so He didn’t come for the purpose of revealing all things to all people. If the Holy Spirit guided all Christians in all truth, there would be no disagreement among Christians, so there has not been a complete revelation to all.
1 Peter 1:5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
Isaiah 25:7-9 And he will destroy in this mountain the face of the covering cast over all people, and the vail that is spread over all nations. He will swallow up death in victory; and the Lord GOD will wipe away tears from off all faces; and the rebuke of his people shall he take away from off all the earth: for the LORD hath spoken it. And it shall be said in that day, Lo, this is our God; we have waited for him, and he will save us: this is the LORD; we have waited for him, we will be glad and rejoice in his salvation.
This passage in Isaiah contains several clues indicating that it is talking about the end times. It talks of God wiping away tears, and about death being swallowed. What is really interesting about this passage is that it also talks about the lifting of a veil, the lifting of a covering that has covered all nations. This suggests that God has actively prevented people from discovering certain knowledge. It would have to be true that the solution to many riddles in the Bible are not complicated.
The clues in the Bible are there, and our reasoning ability is sufficient to solve many riddles in the Bible, and thus God had to keep us from seeing what we should be able to see. A riddle in the Bible can have a very simple solution. There may have been millions of occasions where a person thought of that simple solution, but God could easily have caused the thought to vanish.
That is what is meant by the lifting of a veil. God no longer prevents us from seeing what we should be able to see.
It is the authors of the Gospels who were guided by the Holy Spirit to remember the words of Christ. The authors of the Bible were guided to record the truth even if they did not fully understand the full meaning of what they were writing, and this being the case their words would have to be consistent with each other. The real solution to the Bible would need to fit all the pieces together and be consistent with all the clues. It should also be fairly simple revealing a miracle of God that no one was able to see it.
