"I read it on traditional Catholic website."
Why would you think that that website represents what the Church teaches any more that this one?  Now, they were Christian authors in the sense that they were comporting themselves as believers in Jesus Christ, yet Luke is not Jewish nor does he follow that tradition.  By the time most of the books of the NT were written, Christianity had parted ways with the Jews who, in fact, sought their persecution.

Paul refers to himself as an apostle, which is not an ordained role but a ministry.