What's the justification of eternal torture in hell?

One important point to this sort of question that was overlooked in this discussion is Election and Predestination. Most "humanist" don't take the interest or time to really study Christian Scripture and more importantly, if one is an unbeliever, will find most Christian beliefs foolishness because the revelation of Scripture is only spiritually discerned.

The fallacy of God being required to answer to man's sense of justice notwithstanding, the fallacies with questions relating to the justification of eternal torture are academic relative to the revealed truth of Scripture. God predestined His Elect from eternity and the reprobate will never believe and are condemned already.

The misconception is that we are here to make some sort of "decision for Christ" or, by others, that if we live a "virtuous life" that we will be judged well and permitted into Heaven. These are all false doctrine and the best we can do in this life "filthy rags" to God.

It's simple really, if your name appears in the Book of Life from before the foundation of the world then at some point God the Father will draw you to His Son and you will be saved out of this world. If not you will be condemned to hell. If that seems unfair to the OP or to the UN then, "who indeed are you - a mere human being - to talk back to God?". If this doesn't fit within the humanist's sense of judgement then that's too bad, this is God's Creation. It's all in the Scriptures and quite simple to those who are of the Elect and will always be foolishness to those who are perishing. God bless.

Your 3 questions:

1. What's the justification of eternal torture in hell?

The hell is the "eternal fire prepared for the devil and his angels". Now God give us the choice of follow God or the devil. Why someone that choose follow the devil (or choose do not follow God, in a biblical sense it's similar) will to heaven with the God followers? Is it fair? Now imagine a prison. It's not a nice place... but if you commit a crime, you (hopefully) will end in a prison. Hey, it's YOUR choice is there... You cannot blame the government or society (or even GOD) why you are in a place that was not prepared originally for you...

2. Can the belief in hell be justified against the Convention in those countries?

The God's Justice is far different of human justice. It's a topic for entire books, but you can notice by looking that gay marriage, abortion and another topics are approved in humam justice and not in the God justice...

3. What is the meaning of eternal torture?

Eternal torture is a eternal state of separation from God. Burning fire and torture are the lesser of your problems...

In the literal sense, there is no justification in eternal torture in hell.

The bible is absolutely steeped in symbolism, but gives plenty of "keys" to understanding the symbolisms.

Ecclesiastes 9:5 - Dead are unconscious.

Revelation 20:11-15 - Gehenna (Means second death...so where was the first death?)

Humans seems to like this idea of punishing by fire, but God states such an idea does not even come up into his heart:

Jeremiah 7:31- 32

The above account states that this manner of reasoning (punishment by fire) was directly inspired by pagan worship Jeremiah 7:30, and obviously it still is.

This torment-in-hellfire is an unending debate, but in the bible trees talk, animals with seven heads eat prostitutes, horses are ridden in heaven, locusts sting people. Its certainly not a boring read. But truly, its obvious our God-given intelligent minds were meant to perceive things beyond the strictly literal (John 6:56).

Most importantly religions and prominent leaders have always twisted things to get obedience by morbid fear, but the mind of God is very different: Matthew 11:30, 1 John 4:8.

And before it even goes as far as permanent death, there is always a kind hand out to pull us back from the proverbial fire: Job 33:22-29, Jude 1:23.

With all things considered - eternal punishment by fire (everlasting death) is a strong motivator to turn around given by a loving God, even if a kind outstretched hand is not enough to motivate the heart.

Even though I believe this has been answered elsewhere, I'll go ahead and answer this based on the comments to the original question.

Disclaimer:

Before I do, I need to remind everyone of the narrow scope of this site: We are not focused on proving any particular thing to be true. We focus solely on what the teachings are. As such it would be against site guidelines to answer whether the eternal punishment in Hell is true, or if God was justified to create an eternal place of torment. We can only answer what is taught within Christianity.

I'm going to answer this from the standard protestant Apologetics answer, which shares common themes across denominational boundaries.

The question here, as focused by the comments is "can the belief in hell be justified against the U.N. convention of disallowing torture".

The obvious answer here is the one that God gave to Job when Job questioned him about his misery. "Who are we to question God?"

Job 38:4 (KJV)

Where were you when I laid the foundations of the earth? declare, if you have understanding.

As explained by Matthew Henry's Concise Commentary

For the humbling of Job, God here shows him his ignorance, even concerning the earth and the sea. As we cannot find fault with God's work, so we need not fear concerning it. The works of his providence, as well as the work of creation, never can be broken; and the work of redemption is no less firm, of which Christ himself is both the Foundation and the Corner-stone. The church stands as firm as the earth.

In other words, God does not have to justify torture. (More on this later in the answer)

But that's not what you asked. What you specifically is how we humans can justify the belief in Hell when the U.N. has condemned it.

Again - short answer. We believe it because God said it's true. As pointed out by God in his discussion with Job (And by DJClayworth's comment), God is sovereign. God doesn't answer to us, we answer to Him.

We believe (at least most Christians do) that the Bible is God's inspired, inerrant Word.

Side note: Why we believe that would be the basis of a hundred other questions already answered on this site. And to make a distinction, that we accept this is not an implicit assumption, it is an established doctrine. Remember, we are not here to teach what is True, just what Christianity teaches, and it is undeniable that Christianity teaches that the Bible is God's word. Any attempt to steer this into a direction of whether it really is God's word is strictly not allowed in the site guidelines.

Main answer:

So that's it in a nutshell. We justify our belief because we trust God's word, and His word says it is so. We do not believe that God is accountable to the U.N. or any other organization/being, etc.

Extra credit

Addressing your qualifiers:

The satisfying answer should justify general christian insight without counterquestions, without metaphores, without implicit assumptions, without solipsism and without twisting of meanings.

While I'm at it, however, I'll point out that the underlying assumptions in the question are that:

1. God isn't real
2. The existence of Hell is immoral

In other words, the belief that we need to justify this is based on the assumption that God is a man-made construct. That we, as the group who believes in this made-up being, are responsible for introducing the idea of eternal torture. And that we must somehow answer for it or justify it. That is, in itself an "implicit assumption". It is quite impossible to have an opinion on anything without implicit assumptions. We all have them. We all have a set of glasses through which we see the world, and a base set of implicit assumptions that color our perceptions.

The very idea that "God is not real" generally springs the idea that "I won't believe it if it's not proven to me". In other words, if you can't prove that god exists, to my own satisfaction, then I don't believe He does. Tracing this back further, the root assumption that leads to this is that you are trusting only in your own intellect, mind, and reasoning process. This is the very solipsism you sought to ban in any "satisfying answer".

To bar implicit assumptions and solipsism in an answer to a question that is dripping with them shows a bit of a double standard. But at least I think I avoided the metaphor.

Likely, however, this won't be a "satisfying answer". If you were hoping for someone to come with proof that Hell is justified, I'm sorry, this is the wrong site. We don't focus on what's true, but rather what's taught. You may wish to go to a site dedicated to such things, but this isn't it.