Dealing with anti-Catholics is, for the most part, a waste of time. Nevertheless, if you are confronted, I think there are two things to keep in mind.
First, you have to be friends. Without that, there is nothing from stopping them from slamming down on your toes.
Second, take a minute to examine the underling premises. For example, the point of the confessional. The person usually has all kinds of misperceptions crystallized by a lifetime of prejudice. This is a huge obstacle to overcome before you can bring a person to the point where they are at least willing to consider truths, let alone accept them. The soil is rock hard, and needs tilling before any seeds can take root. And the seeds you plant are actually seeds of doubt that may weaken his belief system, a titanium covered heart. For example, “The confessional is true, because Jesus is God, and God is love, and Jesus loves me enough that he gave HIS power to human priests to forgive sins, because I can’t see Jesus, but I can see and hear Him when He forgives me through the priest. You don’t argue the truth, you present it.
You stop there, and wait for the next insult, because the person is prejudiced, and thinks the confessional is a Catholic invention. He will not trample on the pearl of love, (underlined above) but he will on the pearl of sound doctrine, so you may want to hold that one back. So he tramples on you and says, “Where is that in the bible”.
Don’t give that pearl either…yet. Till the soil. Ask him if he is anti-Semitic, and if he thinks all Jews are going to hell. If he is not some kind of skin-head theologian, he will say of course not. Then you say, “If I show you in the bible where God COMMANDS the Jews to confess their sins to the priest, will you consider a few other verses that supports what I believe?
Here you are maintaining his dignity as a person by asking him for permission, and granting him the freedom to “consider”. Always be prepared to end the conversation, and leave room for God to apply his grace with what you don’t say. It might be best to say, “I’m afraid I am not as blessed with scripture memory as you are, so I will show you in the bible where the Jews practiced confession to the priest, in the OT, as well (if you are not prepared) some other time, or post it the next day. You do agree that what is hidden in the OT, is revealed in the NT? (almost all Protestants agree with this principle)
Friends
God’s love
How God loves us in the OT
How God loves us through his ordained instruments
Maintain his dignity
Maintain yours too by not permitting them to scourge Our Lord (you and me) with scriptures.
Code:
What makes anti-Catholics so blind is not necessarily doctrinal ignorance, but self –hatred. Seeds can’t take root because their hearts are to too hard. So when a sound irrefutable argument is presented to them, they reject it anyway and change the subject.
Self-hatred blinds them to the truth because they are afraid of the Church. And they are afraid of the Church because they are bitter are ex-Catholics or have been taught to be all their lives, or they just hate themselves.
Code:
Therefore it is by the fire of the Holy Spirit operating through your love for them that will melt such titanium hearts. You get this fire in the Eucharist and prayer, the real starting point in dealing with anti-Catholics.
Those are just some reflections.