Why are there no longer large-scale miracles from God? I'll put my frustrations as concisely as I can. I would really appreciate all below points being addressed to some extent.

Why are things not the way they were?

In the old testament, literally millions watched a sea split in two, bread fall from heaven, the earth torn asunder while rebels fell into it, fortress walls crumble on prophetic queue, fire from heaven on more than one occasion, and a number of other miracles (dead raised, axe head floating, leper healed on prophetic queue, etc.) which do not happen anymore...ever.

The prophets of old were legit. They said "x will happen". "x" was very specific and very significant and it was a big deal for their own necks if "x" did not happen. e.g. "Tomorrow the dogs will lick up your blood in this very spot." (somewhere in Kings I think). And boom. It happened. Modern "prophets"? They're panzy and soft. They "prophecy" that "new beginnings will come" and "your family will have a spiritual revival" etc.

I know that Jesus said "the law and the prophets were until John." But why? And why then did John later mention the 2 prophets of revelation (the 2 witnesses)?

Some say that God demands faith and that's just the way it works. We get no "solid proof". But you don't need much faith when a sea is split in two and opens a trail for you, right after a wall of fire spawns itself to separate you from your enemies.

Jesus said "this generation will not be given a sign" when the pharisees asked for one. If I can be frank, Jesus had already given quite a few signs before their request, and after. Voices from heaven, earthquake at crucifixion, dead raised, many many sick healed, transfiguration...

My point is, why has God left the scene of humanity for the past 2000 years, apparently?

It seriously leads one to believe that the ancient stories never happened. But I for one continue in the dilemma because I've researched the Bible quite extensively, and at the least it is quite a legit historical book. The sheer detail in all these stories leads one to believe that they are legit stories. But the sheer absence of such events nowadays leads one to believe they're not.

My struggle would be a lot easier if I watched the Red Sea split in two. You see?

Are we ("this generation", post-Christ) just being subjected to the biggest test of faith in humanity, per Jesus' words, "When the Son of Man returns, will he find faith on the earth?"

And finally -- I have seen documentaries on modern "miracles". First, they pale in comparison to the above-mentioned, and second, they are highly dubious. They are fluffy and questionable, much like those modern "prophecies".
All the miracles haven't gone, rather The Miracle has come.


  John 1:14 (ESV)
  14&nbsp; And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.


All your questions come down to this. The incarnation of Christ changed the tangible state of our relationship to God. The primary job of the prophets was to inform the people about God and his ways and point them towards the salvation found only in Him. When Christ finally came, there was left nothing more that needed revealing.


  Colossians 1:19 (ESV)
  19&nbsp; For in him all the fullness of God was pleased to dwell,


The job that remains is not the job of revelation that the prophets had but  one of declaration. We proclaim that which has already been revealed.


  Acts 4:20 (ESV)
  20&nbsp; for we cannot but speak of what we have seen and heard.”


The miracles of the Old Testament were given as signs to validate the truth of the prophets message and that it was indeed from God. Then God himself came and gave the greatest sign of all.


  Acts 2:32 (ESV)
  32&nbsp; This Jesus God raised up, and of that we all are witnesses.


If you do not believe in the resurrection based on the evidence you have been provided, no miracle will help you.


  My struggle would be a lot easier if I watched the Red Sea split in two. You see?


No, actually, according to the Bible it would not be. Do you seriously think that you are somehow superior to the Israelites? Do you think the nature of man has evolved to be more rational, more pure? Those that watched the Red Sea part and walked across on dry land quickly fell into dis-belief. They promptly doubted God's good intentions and ability to save. You are no different and your faith would not be any easier for having watched it in your lifetime.


  Psalm 78:32 (ESV)
  32&nbsp; In spite of all this, they still sinned;
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; despite his wonders, they did not believe.


The people of Jesus time made the same demand that you are trying to make. You would do well to head Jesus' answer.


  Matthew 12:38-40 (ESV)
  38&nbsp; Then some of the scribes and Pharisees answered him, saying, “Teacher, we wish to see a sign from you.” 39&nbsp; But he answered them, “An evil and adulterous generation seeks for a sign, but no sign will be given to it except the sign of the prophet Jonah. 40&nbsp; For just as Jonah was three days and three nights in the belly of the great fish, so will the Son of Man be three days and three nights in the heart of the earth.


If the resurrection of Christ from the grave is not enough to convince you, no supernatural intervention into your space and time will help. Those who were in a position to know best if the resurrection was a fraud were willing to go to their deaths proclaiming that it was legitimate. You have their testimony.


  John 20:31 (ESV)
  31&nbsp; but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.


According to the Bible, you do not need a miracle. You have what you need to believe, you lack only faith and that is something you cannot conjure up on your own.


  Ephesians 2:8-9 (ESV)
  8&nbsp; For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, 9&nbsp; not a result of works, so that no one may boast.


So pray — not that God would show you a miracle for he has done that in spades — but that he would grant you faith.



Endnotes:


This answer glosses over a number of issues that are bound to come up. The apostles also did miracles that were used to validate their witness and the authority with which they spoke (which is part of why their words are added to the Old Testament to make the canon of Scripture we have today). It also avoids the issue of New Testament gifts and whether it's possible that some gifts continued to be used as miraculous signs after the incarnation. While those issues surely deserve examination, they must be secondary to the realization that the main miracle happened and that we are have been given enough evidence to believe without a miracle. After we come to grips with the fact that our unbelief is sin whether we've seen a miracle with our own eyes or not, then the other issues can be discussed. I focused the body of this answer on the main story line. Get that straight and the other pieces will be easier to fit in the puzzle. Miss the main plot and they will only serve to confuse and confound.