Sometimes I hear people say that it is awfully arrogant for Catholics to believe they are part of the One True Church and that they are the only ones who have the Fullness of Truth.
Something I want to say to that is this:
It's not arrogant when you have been shown the truth and want to share it with others so that they can have what you have. It's not arrogant when you know that it is only by the Grace of God and not by your own merits that you have faith in the first place. It is not arrogant when you believe in something so strongly that all you want is to bring others to it so that they can feel the same joy and peace in your own heart.
It is only arrogant when you hoard it and keep it secret, saying "This is mine; I am better than you; you can't have what I have."
Don't be arrogant--share the faith!