When I am defending the Church, Catholics are the biggest obstacles. I remember more than once explaining the Church's teachings, only to have the person that I was talking to say "Oh, my sister-in-law is Catholic, and she doesn't believe that." Well, it's what the Church teaches. Or someone is looking into the possibility of joining the Catholic Church but they are put off by the huge numbers of Catholics that seem to have no concept of who Jesus is.
This state of things regularly frustrates me, as well as convicts me. Sometimes the question comes up in my mind: How can this be the true Church if there are so many Catholics in it? How can there be so many graces flowing from the sacraments, if people seem untouched?
That is one of the reasons that I like Romans so far. First of all, it reminds me again that as a Catholic, the Jews are my spiritual ancestors. I read in the Old Testament how they screwed up (I think they once went a couple of hundred years without celebrating the Passover, they had fallen so far away from God) and I realize that we screw up a lot as well. It isn't that it excuses us, but I can recognize that the Jews were God's people because He chose them, and not because they were such exemplary people. The Catholic Church is God's because He founded it and keeps it, not because of the Catholics in it.
"To begin with the Jews were entrusted with the oracles of God. What if some were unfaithful? Does their faithlessness nullify the faithfulness of God? By no means! Let God be true though every man be false."