The Roman Catholic Church is the single largest religious body in the United States and has the oldest continual existence. Nearly one in four Americans is a member if the Catholic Church making up about 63.4 million professing Catholics. By and large, Catholics make up a sizable part of the United States’ population, living and working among people from a number of different religious beliefs. There are challenges in presenting the Gospel to staunch adherents of the Catholic faith. This presents an evangelist with a superlative opportunity to present the Gospel to someone who already believes they have the truth. The Gospel of Jesus Christ does not change. No matter to whom one is witnessing, whether an Agnostic or Catholic, the Gospel remains the same. The common way to witness is to simply present the plain truth of the Gospel of Jesus Christ. After having heard the simple Gospel, if a person does not want to be saved, then they do not want to be saved. There are no words of wisdom to convince the skeptic who does not want salvation, the truth—the Gospel cannot be compromised to match personal philosophy. If a person will not obey the simple Gospel, then he will not listen to the words of wisdom Paul said to the Corinth church… “For Christ did not send me to baptize, but to preach the gospel, not in cleverness of speech, so that the cross of Christ would not be made void.” One must determine what he is attempting to discuss, and that is the Gospel of Jesus Christ. It is a word of Anglo-Saxon origin, and meaning “God's spell,” i.e., word of God, or rather, according to others, “good spell,” i.e., good news. It is the rendering of the Greek , i.e., "good message." It denotes “the welcome intelligence of salvation to man as preached by our Lord and his followers.” Roman Catholics and Baptists have much in common doctrinally. Both groups are monotheists, worshiping the one living God, Creator of Heaven and earth and all that is in them. Both believe that God is spirit and therefore invisible, that He has revealed Himself to men as recorded in the Bible. Both accept the records of the four Gospels concerning His teaching and miracles, Jesus’ suffering upon the cross to atone for our sins, His burial, and His resurrection on the third day, and then His ascension to Heaven after forty days. The doctrines common to both Catholics and Baptists are many, but the differences which divide them are also many and very great. Generally speaking, these differences spring from two fundamental roots of the authority of Scripture and salvation.
The Roman Catholic Church says the Bible, by itself, does not cover the whole field of revelation and that it has been supplemented by the teachings and decisions of the “Holy Mother Church,” and the Pope as the “Vicar of Christ. The Roman Catholic Church has an unbiblical understanding of justification. This can be seen in the following quotations from the Catechism of the Catholic Church, which asserts (1) that justification is initially granted to an individual through baptism; (2) that justification is maintained through the sacraments of the church; and (3) that justification ultimately depends on the obedience of man by which he merits eternal life. Thus, by Scriptural standards, the Roman Catholic Church is a false church that can only expect God's judgment, not a true church that can claim God's blessing.
With that in mind, when witnessing to Catholics the evangelist is presented with a number of areas of concern: salvation through faith by grace alone, salvation in Christ alone, the Virgin Mary, purgatory, and that the Apocryphal books have been added to Bible. Catholicism is fairly easy to expose as a cult, it is getting people to forsake their family and church traditions that is most difficult. The hardest part of soul-winning is not getting people saved, it is getting them lost. The evangelist must be delicate with his approach of Catholics with the