Rome lacked the last two.
Christianity was the exclusive state religion of the Roman Emprie since 381 AD and barbarians served in Roman armies already long before that.
So Rome did not lack those two things. All barbarians who settled within the borders of the Roman Empire adopted Christianity from Rome.
Everybody uses english now as a "communication" language, I don't think it can really be used as a "civ divider".
This is why the fact that we are using Latin alphabet is more important. And Latin language terms are still widely used in law, sciences, etc.
Not to mention that we have plenty of words which originate from Latin in our languages. English language also has a lot of terms from Latin.
French as well as all other Romance languages (Spanish, Italian, Portuguese, Romanian, etc.) actually evolved directly from dialects of Latin.
Rome was a mediterranean civilisation.
Not only:
http://en.wikipedia.org/wiki/Hadrian's_Wall
Here is a map of Roman roads:
http://omnesviae.org/de/
And temporarily - before the battle of Teutoburg Forest - Roman north-eastern border was even farther east, along the Elbe River.
Contrary to popular beliefs, after Teutoburg, Romans didn't stop penetrating into Germania.
Just to mention the invasion by Germanicus (this one is commonly known, unlike several other ones):
http://en.wikipedia.org/wiki/Germanicus
Later - in 235 AD - Roman legions under command of Maximius Thrax penetrated several hundred Roman miles into Germania (according to "Historia Augusta"). In 2010 a team of archaeologists led by Petry Loenne discovered near the village of Hachelbich (Thuringia) a Roman military camp for 5,000 soldiers constructed during the 3rd century AD (see the link below). Another very similar camp was discovered near Göttingen in 2008.
"Ancient Roman Military Camp Unearthed in Eastern Germany":
http://news.sciencemag.org/archaeology/2014/05/ancient-roman-military-camp-unearthed-eastern-germany
And before Teutoburg, a few years BC, according to Tacitus (IV, 44), Lucius Domitius Ahenobarbus with his army, sent by Emperor Augustus, crossed the River Elbe penetrating farther east than any Roman before him. Findings of Roman weapons along the Oder River are quite frequent. New archaeological findings such as camp for 5,000 soldiers discovered near Hachelbich are moving the eastern extent of areas controlled by Rome (at some point in time) further and further east. There were also naval expeditions. According to Pliny and "Res Getae", Roman fleet entered the Baltic Sea during the regin of Emperor Augustus.
There is also evidence of Roman colonization inside Germania - remains of a Roman city were discovered near modern Waldgirmes:
http://en.wikipedia.org/wiki/Waldgirmes_Forum
Those things described above was penetration of Germania from the western direction (from Gaul).
There was also penetration of "Barbaricum" - both "Germania" and "European Sarmatia" - from the southern direction. For example expeditions during the reigns of Emperors Nero and Domitian, Roman military camp discovered in Trencin near the Carpathian Mountains, the Amber Road, Marcomannic Wars, Roman plans of creating new provinces of Marcommania and European Sarmatia, etc.
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This is how
Ptolemy defined boundaries of regions called by him "Germania" and "European Sarmatia":
BTW - "Germania" literally means "Land of Neighbours" and "German" / "Germanic" means "Neighbour" / "Neighbouring":
http://en.wiktionary.org/wiki/Germania#Etymology
The name "Germania" came into use after Julius Caesar adopted it from a Gaulish term for the peoples east of the Rhine that likely meant "neighbor".[1][2]