Re: "...the 12 disiples were ALL Jews..."
True.
During Christendom's early years, non-Jews first converted to Judaism before they were allowed to follow Jesus.
The Greek physician named Luke was one such person.
The earliest "Christians" were simply Jews who truly believed Jesus to be the promised Jewish Moshiach.
Only later, when the Apostle Paul (a Jew named Saul who had spent his early years hunting down apostate Jewish followers of Jesus to prosecute them as heretics) was given permission at Jerusalem by the other disciples to preach exclusively to the gentiles, did the faith actually break away from its foundations, as "Paulism" spread throughout the Roman Empire and became the predominant faith.
In fact, without Judaism, Christians and Muslims would not exist, as each claim to be the "final fulfillment" of Judaism.
*Will a forum member please identify the name "Theotokus" for my benefit? Is this a personage or an article of the Greek Orthodox faith?