All prophecy speaks in symbolic and visual language, and as such becomes a language of its own. For instance, Gods presence in the Bible is shown visually to be fire; the tongues of fire above the apostles in the books of acts showed God's Holy Spirit upon them. The burning bush that Moses saw represented God's presence there. Paul describes Jesus second coming as in blazing fire.
Therefore, when we think of fire, or see a prophetic announcement regarding fire, we see the presence of God in it.
In general, God presence can be positive, or judgement. As God's people it's always a positive experience, worshipful, beautiful and 100% victorious. If your not among His people, then Jesus's eyes blazing with fire, speaks of the judgment, justice meted out.
The mountain of fire that is cast into the sea wherein 1/3 part of the sea became blood in Revelation 8:8 is showing in very visual Biblical language very specific things, and when you know the Bible well you see what those things are.
First, this is a judgment involving God's presence, as we see with the fire. Second in the Bible mountains represent kingdom's, so it's a judgment involving a kingdom represented by the sea. The "sea" in the Bible is always the sea of people around the Mediterranean, so we know it's a judgment surrounding a kingdom in the Mediterranean region.
When we read Jeremiah, we see this mountain:
"Behold, I am against thee, O destroying mountain, saith the Lord, which destroyest all the earth; and I will stretch out mine hand upon thee, and roll thee down from the rocks, and will make thee a burnt mountain" (Jeremiah 51:25).
The mountain was the emblem in Jeremiah's prophecy, of the strong consolidated power and institutions of the Babylonian kingdom so it's easy to see the judgement spoken of in Revelation to be a divine judgement upon a nation's/kingdom's consolidated power and institutions that stand in opposition to God, and thus also God's people who it persecutes.
However, it is the power of God's advancing cause which has the power to hurl the rooted mountains from their base. The power of faith, Christ declared, would suffice to do this (Matthew 21:21).... so we have a blessed hope, that no matter what they do to us, through faith and God's might we will rise victorious. They might kill our bodies, but they will never win this battle.
We see this judgment upon Babylon in Revelation 18 again, with a clearer eye and we see God's people saved from falling into the traps of this world, called to our Lord's saving grace and then God institute's justice:
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Give back to her as she has given; pay her back double for what she has done. Pour her a double portion from her own cup."
Why is the Kingdom judged so? We are told:
"Rejoice over her, you heavens! Rejoice, you people of God! Rejoice, apostles and prophets! For God has judged her with the judgment she imposed on you.".... "In her was found the blood of prophets and of God's holy people, of all who have been slaughtered on the earth."
So she is guilty for persecution of God people, and her destruction and judgements aren't a time of mourning, they are a time of victory and great celebration, for God has prevailed!
I could go on to more examples, but I'Il leave it here as this is just to give you an idea of what prophetic visual language shows.
There's really nothing bad in Revelation unless your scared of judgment upon your own head... if you fear judgment, you should probably pray and read scripture and earnestly seek assurance in your own salvation... because not feeling assured that you are indeed a child of God is the only thing that should worry you about it.
God's presence upon the earth, however, is an awesome and beautiful thing, for God's people, even when it lays bare the sins of nations and judges them because it brings some to life and to repentance.
"And in those days, I will pour our my Spirit upon all people's..."
We live in those days.
"And everyone who calls on the name of the Lord will be saved.' "
God will prevail over all the machinations of man. He will prevail in China. HE will prevail over Islam. He will prevail over communism. He will prevail over socialism. Whatever man thinks up. Whatever Satan institute's. God and His people prevail. A promise not a fear.
Editing to add:
Lamentations 3:39-40
Why should the living complain when punished for their sins? Let us examine our ways and test them, and let us return to the LORD.
"We were created for the Lord's Glory. Do you desire His Glory? Well, what if the Lord's Glory requires vindicating Himself? This is what we should ask ourselves. What if God gathering glory to Himself came at a personal cost to ourselves, to our comfort? Would we still welcome His Glory? The question is always where is God in our thinking..." - Pastor Robert McCurley of Greenville Presbyterian Church.
