In my view as a former devout Roman Catholic, the RCC is one of the most ignored mission fields on the planet. Here are some pointers to keep in mind.
1. Roman Catholicism teaches another gospel. The Catholic is led to believe Jesus Christ’s work on the Cross was never enough to save them. It was merely a grand gesture, and now it is up to them to complete His work.
2. Approach a Catholic like you would any other unbeliever or world religion. There is no need to tip toe around the truth, or walk on egg shells. Remember it is not you who is the converter, but God, and ask yourself are you expecting praise or desiring their salvation. Don’t buy the guilt virtue signaling, “you are a hater” or “you are bigoted”, if you are anti-sin and you love God with your whole heart, soul, and mind, it eliminates that silly argument.
3. Catholics are good people in our communities, but don’t let this cloud the fact that they need the Gospel. They may speak of “grace”, “Jesus Christ”, but I assure you their meaning and Scripture’s meaning are two vastly different ideas.
4. Catholics already believe they are Christians. They are not easier to witness to than atheists, but quite the contrary. They were led to believe by their church-going, sacraments, creeds, and tradition fallacies that they are the church. So it is VERY important you establish with them what the church is.
5. Manipulating and conforming to Catholicism never works. There is one common ground I can think of, they know there is an eternal hell. So it is very important to establish why one would go to hell, our sin problem, and the only way to remedy this problem will be by the person and work of Jesus Christ, not smoke, incense, and rituals.
6. Ask them for their PERSONAL testimony in Jesus Christ. They simply will not have one. We should be hearing the decades long description of a relationship with the King of kings. Too often, I’d say even outside the RCC this is a missing element. If you don’t have a testimony, how is a Catholic going to trust you that the Good News of Jesus Christ changed your life?
7. Catholicism is NOT Christianity. It uses its name, that’s all. I say this boldly and without an apology. It is not anti-Catholic, it is being anti-SIN! They may speak of Jesus, quote Scripture, but it is always the RCC’s version, it isn’t the Messiah, the Lord of lords, but their version. Important to keep this in mind.
8. If you are worried about offending feelings, ask yourself if your Catholic neighbor, friend, or family member passed away tonight and you withheld the truth, where would that leave you? In regret! We aren’t promised tomorrow, the time is short and urgent! If they scoff and mock and do not want to speak to you anymore, is that really your problem or theirs? Do not be ashamed of the Gospel!
9. If you have a Catholic close to you, try to read the Bible with them! Read it out loud and let the word of God do the rest.