Works for me since I wouldn't be able to understand Catholecism by reading the NT either. Makes sense.
You could understand much about Catholicism, at least what Catholicism ASPIRES TO BE, by reading the New Testament.
However, if you do as a good Jew would do, and look at fruit, at acts, at history and not just at words and aspirations and doctrines - at what is DONE and not just what is SAID TO BE BELIEVED - then you would indeed find quite a bit of Catholic history that is diametrically opposed to what Jesus said. And in that sense, reading the New Testament and then comparing to, say, the Spanish Inquisition, you would realize that the Catholic Church has not always followed Jesus' example literally (or even figuratively, in such cases).
You confusion would be justified.