Are the Christians to Blame for the End of the Western Roman Empire?

No... almost nothing you said is true...

The Western Roman Empire existed from 395 to 476 CE. 313 CE, when Constantine ordered Christianity to be legalized, it was still a combined Roman Empire.

The Roman Empire was not peaceful and tolerant before Constantine decided to unite the empire under Christianity. He fought a civil war between 306 and 312 CE. And there was plenty of war in the Roman Empire prior to Constantine's rein, like the conquest of Britain in the 1st c. CE, the Roman-Persian wars in the 2nd c. CE, Gothic and Allemannic wars in the 3rd c. CE, Jewish-Roman war and uprising, etc...

The fall of the Western Roman Empire was largely due to the fact that the Empire became too spread out for the outlying regions to be properly governed and adequately protected from far away in the central capital.

In addition, even though the Western Empire fell, the highly religious Eastern Roman Empire continued to prosper for another 1000 years, reclaiming a lot of territory that was once the province of the West. Not to mention that the successor Holy Roman Empire which controlled much of Central Europe through the end of the 18th c. CE was also Christian. So your premise that Christianity caused the fall of the Empire would make more sense if we saw similar results in the other Roman Empires.

So you flunked Early World History, huh??

It is certainly true that an empire that had stood for many centuries fell shortly after Christianity was made the official religion.

Strange - I thought the Roman Empire had gone down in history as the most barbaric one there had ever been. Well, who was (not 'IS') to blame for the end of the Western Roman Empire? You are right to say 'Western'. That's because the fall was due to the Western Empire becoming much poorer than the Eastern Empire in the 2-300 years before the Vandals attacked. The basic problem was that too many non-productive members of the society had to be fed by too few productive laborers. The army had doubled in size since the 3rd century and bureaucracy had expanded considerably, while the number of producers had shrunk.

Meanwhile, great landowners who held a massive proportion of the Empire's wealth, frustrated imperial attempts to make them pay a fair share of taxes. Yet the weaker West was exposed to a more severe and prolonged attack than the East. In 393 non-Catholics were removed from all government posts. You may rightly point the finger at Catholics then controlling the government and the civil service with resulting creaming-off for the East and impoverishment of the West. That's why the Western side collapsed.

What did the collapse have to do with religious debates within Catholicism? All the Christians who disagreed with the pope's authority became persecuted by the Catholics, hounded out, some were even killed, and many had to flee. They held no positions of office either in Catholicism or the Empire, so you can't blame the fall on those non-Catholic Christians! Think well on that, and stop trying to tar everybody with your brush. And stop asking rhetorical questions that are useless to answer (like, 'What should the Emperors have done to prevent the fall of the Western Empire?') A relevant question would be, 'What similarities today do we see in Russian taxation and its hand-in-glove cosying-up to Russian Orthodoxy in politics?'

Jesus Christ preach the oneness of GOD only to the Jews ,and has nothing to do with the non -Jews ,as of the Roman. So how come the all the Popes of Roman Catholics churches claim themselves to be the disciples of Jesus. GOD command Jesus to appoint his 12 Disciples who were from the Jewish family only, then nothing to do with the European Pope of the Roman ,who were non Jewish, even Vatican has nothing to do with the Holy Land of Jesus Christ. So the Roman were to be blamed ,that is why

Don't try blame that on ME, dude! Back when I was a Christian, it was already like that.

Yes, I think probably Christianity was the cause of the collapse, but not for the reasons you suggest.  It's more because people started to focus on the hereafter and abandoned their civic duties.

Specifically it was the Catholic church that took, as most person in high offices were pretending to be Catholic and making load of money. This is the reason the Catholics have their own little country today; named the Vatican. If  religion has its own country, you ought to know that something is not right.

The Pantheon 'the temple to all the gods', Maison Carrée and the Arch of Titus survived. Gratiae ut Caesar Augusti.

They should have accepted the christian religion and lived on together in the future.