Dalibor, according to your first post here – you said:
I am affraid you got something wrong in your paradigm of history.
Romans were pagans. And they were persecuting Christians.

Yes I did wrote so. You could read similary statements in almost hictoric any book dealing with question, Christian or not Christian.

Romans didn't perceived themselves as pagans.

So? We are not comunicating in III century Latin, but in English. In English word pagan has same meaning as polytheist. Hope now you understand what I meant.

This term was used according to "a villager" or "a civilian"

If you are vilager you cant be civilian (in Latin language and Roman worldview). Civis was citizen (of Rome). Word paganus has meaning of civilian in sense of military unexpirienced man, but it was military jargon.

When people started to convert to Christianity, this term became a word that describes non-Christians.

Not exactly. I said it was rather local phenomena, few centures after first conversions (1st century AD), and even few centuries after mass conversion (4th century AD)


But Romans who were not Christians at the time of converting, still were seeing those Christians as pagans, as they mostly lived in a village.

Christians did not live in villages, generaly until IV century. From its begining Christianity was urban phenomenon. All we have from Christian archeology, point us, Christians, almost exclusively lived in towns. Also, if you read New Testament, you can see this. Same goes with works of Church fathers.
Well, to cut it short, Christians were never seen as pagans by anyone. And, again in English word pagan has verry well defined meaning, so honestly, what is essential fallacy of my words?

Ancient Rome was generally tolerating in case of religion  – countries which Rome conquered had right to practise they own native religion.

Yes and no. They were free to believe or not believe whatever they wished, but according Roman Law, every citizen of Roman Empire (from 212 AD, all inhabitants), or every person under its rule, was required participate in worship for Emperor (and latter worship of Emperor). As far as they participated in Roman cultus, they were free to believe whatever they wished, or wished not. Romans, were verry inclusive, and allways ready to accept deities of conquered nations in their beliefe systems. Whoever refused to do so, was considered as unloyal citizen, and even more it was offence Lèse-majesté, and by definition subject of capital punihment. Only exception from this rule was Jewish Religion, which was protected, by another priciple of Roman Law, due to its ancient origin.

Christianity was an exception as people have seen in christianity a danger.

First thing first, Roman Empire was Monarchy, Emperor was sharing his power with landowning, military and lawmaking/lawpracticing elite, people, Roman or conquered had little if any say in state politics. Second, there is famous correspondence between Plinius the Younger and Emperor Trajan, maybe it would be good for you to read it, if you really wish to understand why Romans were persecuting Christians:


It is my practice, my lord, to refer to you all matters concerning which I am in doubt. For who can better give guidance to my hesitation or inform my ignorance? I have never participated in trials of Christians. I therefore do not know what offenses it is the practice to punish or investigate, and to what extent. And I have been not a little hesitant as to whether there should be any distinction on account of age or no difference between the very young and the more mature; whether pardon is to be granted for repentance, or, if a man has once been a Christian, it does him no good to have ceased to be one; whether the name itself, even without offenses, or only the offenses associated with the name are to be punished.

Meanwhile, in the case of those who were denounced to me as Christians, I have observed the following procedure: I interrogated these as to whether they were Christians; those who confessed I interrogated a second and a third time, threatening them with punishment; those who persisted I ordered executed. For I had no doubt that, whatever the nature of their creed, stubbornness and inflexible obstinacy surely deserve to be punished. There were others possessed of the same folly; but because they were Roman citizens, I signed an order for them to be transferred to Rome.

Soon accusations spread, as usually happens, because of the proceedings going on, and several incidents occurred. An anonymous document was published containing the names of many persons. Those who denied that they were or had been Christians, when they invoked the gods in words dictated by me, offered prayer with incense and wine to your image, which I had ordered to be brought for this purpose together with statues of the gods, and moreover cursed Christ–none of which those who are really Christians, it is said, can be forced to do–these I thought should be discharged. Others named by the informer declared that they were Christians, but then denied it, asserting that they had been but had ceased to be, some three years before, others many years, some as much as twenty-five years. They all worshipped your image and the statues of the gods, and cursed Christ.

They asserted, however, that the sum and substance of their fault or error had been that they were accustomed to meet on a fixed day before dawn and sing responsively a hymn to Christ as to a god, and to bind themselves by oath, not to some crime, but not to commit fraud, theft, or adultery, not falsify their trust, nor to refuse to return a trust when called upon to do so. When this was over, it was their custom to depart and to assemble again to partake of food–but ordinary and innocent food. Even this, they affirmed, they had ceased to do after my edict by which, in accordance with your instructions, I had forbidden political associations. Accordingly, I judged it all the more necessary to find out what the truth was by torturing two female slaves who were called deaconesses. But I discovered nothing else but depraved, excessive superstition.

I therefore postponed the investigation and hastened to consult you. For the matter seemed to me to warrant consulting you, especially because of the number involved. For many persons of every age, every rank, and also of both sexes are and will be endangered. For the contagion of this superstition has spread not only to the cities but also to the villages and farms. But it seems possible to check and cure it. It is certainly quite clear that the temples, which had been almost deserted, have begun to be frequented, that the established religious rites, long neglected, are being resumed, and that from everywhere sacrificial animals are coming, for which until now very few purchasers could be found. Hence it is easy to imagine what a multitude of people can be reformed if an opportunity for repentance is afforded.

Trajan to Pliny the Younger

You observed proper procedure, my dear Pliny, in sifting the cases of those who had been denounced to you as Christians. For it is not possible to lay down any general rule to serve as a kind of fixed standard. They are not to be sought out; if they are denounced and proved guilty, they are to be punished, with this reservation, that whoever denies that he is a Christian and really proves it–that is, by worshiping our gods–even though he was under suspicion in the past, shall obtain pardon through repentance. But anonymously posted accusations ought to have no place in any prosecution. For this is both a dangerous kind of precedent and out of keeping with the spirit of our age.

So Christians dont acctually commit any crime, but they should be punished for being Christians.
Please note, that punishment in language of that time means capital punishment.
Also, it should be noted that Traja outlawed all social clubs (verry wide subset of formal and informla societies, from religious sects, to firemen clubs) because of possible political involvment. Christians simply fell unt this category.

And they were right – nowadays "pagans" are perceived as satan's children or heretics,

This is simply false. First, Christians do not believe Satan has children, well there is insult which was usualy thrown
at other Christians faces. But, according Christian teachings all people are created in Image of God, and are considerd as children of Him. Apropo "heretics", wut?  Heretic is, by definition, Christian with unconventian, heterodox teachings.

Anyway, I dont know if you acctually heard of this, but ordinary Roman People tought Christians are eathing their own children, engage in incest etc. Seems we again have bit wrong historic paradigm.

in some radical Christian societies. 

Well, Christians polemicits are offten verry harsh, but for sure favour was allways returned to them, from Jewish opoenents of Christ to Richard Dawkins.

It is even difficult in family to become non-Christian if parents are.

And modern times proved it numerous times.


They like to criticise, it happens sometimes.

Well seems you like to criticise too, for example Chrisitans for calling Pagans heretics, altough it would be bit oxymoron. But, again, love to criticise others is hardly unique to Christians

But in Rome there was generally no matter who believe in what.

As much as you were ready to participate in Imperial cult. What you acctually believed was unimportnant to Government. But it is still not right to kill inocent and loyal subjects, because they were refusing to participate in Imperial cult on gorunds of consceinscness. As far as Christians were mostly of Jewish origins, and as Government was not able to distinguish them from Jews, or simply did not care (Yes many Emperors simply did not care, and we had large periods when Christians were left alone) they were left alone, otherwise they were be killed, if they dont renounce Christianity it is.

Even pagans themselves, who believed in different gods were able to communicate,

And how it is relevant for Christians?

but Christianity, as monotheistic religion, where was told: "You will not have different gods than me" (10 tenets, I don't know if I translated it correctly) suggests that Christians… well.

Well? What well? First, Christians share good part of scriptures with Jews, who were also monotheists, and unlike Christians, they posed real political threat to Roman Empire (they rebelled few times). But Jews were, well left to practicise their religion freely, while Christians ought to do so in secret, if they did go to do it in public, well they were killed. Seems verry, well, unfair. :D

Even not suggests but they expanded in bloody way very often.

They could not even gather freely in public, because they would be arrested and executed, yett they had means to expand in bloody way? Seems quite logical. Christians were pretty small fraction of society, with limited finacial and no political and military ressources untll much latter. Spread of Christianity, in first centuries was without any doubt consequece of Charismatic and Intelectual cpability of its leaders.

Romans seen danger in Christianity (except of Neron's insanity) which was not seen in other religions.

Yes. But it does not mean they were right, and that danger was real. Roman Empire continued to exist till 1453 AD, as Christian state.