I highly doubt that.
A lot of people like to point to the fact that a majority of people in the world are Christian. This, for some reason, validates their belief in Christianity and makes its doctrine fact. They’ll point it out whenever you talk about it too, because for some reason there is this common belief that the truth is democratic. It’s a delusion. An obscure one, yes, but a delusion nonetheless. There are a few major factors that really led to the ubiquity of Christianity in the world, but there is one reason that stands above them all:
Emperor Constantine, watching his empire being torn apart by warring Christian and Pagan factions, made a critical move in the year 333 CE. He converted to Christianity, thereby making it the religion of the Empire. It wasn’t long after that the Council of Nicaea was held, wherein the doctrine of the Roman Catholic Church* was drawn up, specific details about the divinity of the Christ were sorted out, and the books of the Bible (the ones that they wanted anyways) were brought together and combined. The Romans built churches all across the Empire (most of Europe), gave the church power, and forced their citizens to convert, usually under penalty.
It didn’t take long for the Romans to spread Christianity across Europe. In fact, it only took them a century to forget about Mars and Venus. Though, the founding of the church wasn't the most important part of the spreading of Christianity. The real important factor was what happened after the Empire fell in 476 CE.
With all of the political institutions of the Empire nullified, only one organization was left with any power: the Catholic Church. The “kingdoms” that were established by the Franks, Goths, and other Germanic tribes after the fall of the Empire had very little power. By that matter, the Church became the only real governing authority in the lands, even though their former empire was gone. No kingdom in Europe at that time was not subject to the rule of the church (except, maybe the Scandinavians. Vikings!).
This is the factor that really led to the dominance of Christianity. When the Roman Empire fell, the Church stepped in and filled that power void. Its power ranged from the individual people, to the rulers of the new kingdoms themselves.
This is also a good example of why we have the first amendment. It wasn’t long before Christian Europe went to war, and we all know what happened with the Crusades, the Inquisition, old imperialism, etc. All of those events that spread Christianity are the result of the filling of the power void left after the Roman Empire by the Catholic Church. It did not become widespread by the choice of the individuals.
This raises an interesting question. What if Constantine hadn’t converted and Rome stayed Pagan? Could we have been America, one nation under Jupiter?
* Catholic is derived from the Greek word that means “universal”, which is a reference to the fact that at the time the Church of Rome represented all Christians.