The steady flow of converted Roman Catholics, leaving their old "church" to follow Jesus, shows that Catholics can be reached! But the system of idolatry deceiving them is so clever that one cannot hope to be an effective witness to Catholics without preparation. Here are some basic suggestions to help you.
The Apostle Paul was so effective in his ministry of evangelism partly because of his familiarity with the tradition of those to whom he spoke. Romanism is no exception to the rule. You must know at least the fundamentals of their faith. If you don't know what you are talking about, they will detect it quickly.
Study Catholic theological terms. Can you define: sacrament, sanctifying grace, absolution, mortal sin, purgatory, penance, tradition, indulgence, immaculate conception and infallibility? Compare you definitions with those given in a Roman catechism.
Roman Catholics might readily agree that we must be saved by grace. But if you know what they mean by the term "grace," you will see that they do not agree at all! Their church teaches that this grace is stored in a heavenly container and flows into the souls of the faithful through the sacraments of the Roman church. They believe that no salvation is possible, unless dispensed by a Roman priest!
You could tell the Catholic that you have studied Catholic doctrine, and because of what you have learned, you could never become a Roman Catholic. This may often result in a question which will open the door to presenting Bible truth.
Be Prepared to Take Time
You will seldom win a Roman Catholic to Christ the first time you talk. He will need time to think about the new things you tell him. At times, he may be angry as he sees that his church has lied to him. Be prepared to watch and listen, and know when to stop and continue another time.
Establish the Scriptures as Your Foundation
To deal with resistance against the Scriptures, you can quote a Roman Catholic Church Father, St. Jerome, who said: "Ignorance of the Scriptures is ignorance of Christ." Point out to the Catholic that people often don't really know Christ because they do not read the Bible.
If additional help is needed in this area, by prepared to share !! Timothy 3:15-16. Point out that Timothy knew the Scriptures from his youth, and that all apostolic believers had this kind of knowledge. Convince him of the importance of knowing the true Gospel (Galatians 1:8-9, II Thess. 1:7-9).
Destroy Faith in False Gospel
The Catholic can never be persuaded to trust in the Gospel of Scriptures until he first abandons the false gospel of works taught by Rome. YOU MUST MAKE HIM SEE THE HOPELESSNESS OF SALVATION IN THE CHURCH OF ROME. He will not open his heart to saving faith until you destroy his trust in his priest, his "infallible" pope, and Mary as his mediator.
Basic Roman Catholic doctrines have been certified by "infallible" popes. Once you prove even one or two of these wrong by Scripture, he will have doubts about whether or not the pope is right on the rest.
Don't Be Afraid of Controversy
While a contentious spirit is certainly to be avoided, even the apostles often had to use controversy in evangelism, and rejoiced in it (see Acts 13:44-48). Martin Luther certainly caused controversy with his 95 theses, launching a Reformation that led millions to Christ!
Always remember that controversy must not be allowed to decay into a quarrel, where your goal of helping the Catholic escape from bondage is forgotten.
Teach Him the True Gospel
Once you have cut the Catholic adrift from his former trust in his priest and Romish system, you must make the true Gospel clear to him. Our thanks to Wilson Ewin for the following simple explanation which could be easily marked in the margins of your Bible:
Be Prepared for Objections
Even if he cannot remember everything you say, the Catholic will remember that you answered his objections from Scripture. Here are some Scriptures to help with some common problems areas.
Authority of Scripture Higher Than Tradition:
Mark 7:5-13, II Timothy 3:15-17
Assurance of Salvation Possible:
Luke 23:43, Philippians 1:20-23
(Paul had confidence)
No More Priesthood:
I Timothy 2:5
Hebrews 9:24-28, Hebrews 10:11, 12, 14, 18
I Timothy 3:2-4, I Timothy 4:1, 3
I Timothy 2:5, John 14:6, Acts 4:12