It is easy for us as 21st Century Christians to fail to appreciate the historic significance of where we are in the reading of the Acts of the Apostles. Throughout the life of Jesus and until this point in the story what we now call Christianity was merely a sect of Judaism with no sense of being or ever becoming a unique religion of its own, and no desire on the part of many disciples change. The idea that the gentiles would ever "take over" was crazy.
To understand the mixture of feelings in the community, we have only to look at the feelings of Catholics in the US as the Catholic Church shifts from being white western European, or European, to Latino or Hispanic. On the one hand parishes are glad to have the numbers, on the other hand the lose of control, change in language and custom causes great anger and confusion. I recently read an article about angry parishioners in Pennsylvania going so far as to call the closing of Eastern European Catholic Churches as "ethnic cleansing." Nevermind the fact that the churches in question are all but empty and there is no new way of immigrants from those countries to fill them. Such logic is lost.
In our heads we can quote the gospels about love and unity, but in our hearts the desire to cling to what we think is rightfully ours takes over. We forget that it is not "our Church" or even less "my Church" The Church belongs to God and in every time and place it changes according to his will.
The Hebrew church Jesus founded transformed into the Greek speaking, and later into the Latin based church we think of in the US as the predominately Latin Rite Roman Catholic Church, the Holy Spirit continues to transform us, until the return of Christ.