I am amazed that you are so quickly deserting Him who called you by the grace of Christ, for a different gospel; Which is really not another; only there are some who are disturbing you and want to distort the gospel of Christ. But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed! (Galatians 1:6-9)
There are over one billion professing Roman Catholics in the world, second only to the Muslim faith. There are approximately 78 million Catholics in the United States making Roman Catholicism the largest single religious denomination in the United States, comprising about 22 percent of the population. There are millions of very prominent and influential people, including politicians, business leaders, educators, media personalities, professional athletes and entertainment celebrities who are Catholics. But are Catholics really Christians?
The Roman Catholic Church and so called "born-again" Evangelical Protestants certainly agree on many moral and political issues, including our opposition to abortion, the homosexual agenda and other moral and political issues. Most Catholics I have known are sincere in their faith in God. As the Apostle Paul wrote about his fellow Jews; Brethren, my heart's desire and my prayer to God for them is for their salvation. For I testify about them that they have a zeal for God, but not in accordance with knowledge. (Romans 10:1-2)
However, sincere zeal and motives and like positions on political and moral issues does not bridge the wide doctrinal gap between what Roman Catholicism teaches and what is the true gospel of our Lord Jesus Christ. Those who hold to the basic doctrines of Roman Catholicism such as a "works" salvation, the Mass and the Eucharist or perpetual sacrifice of Christ, the worship of Mary, the mother of Christ, and the divinely appointed authority of the Pope and Bishops, have distorted the true gospel and are not true Christians.
For more information regarding the many doctrinal differences I recommend a book by James G. McCarthy, himself a former Catholic, entitled "The Gospel According to Rome". In his book, McCarthy compares in much detail Catholic tradition and doctrine with the truth of the Word of God.
I have known of many people who were formerly Catholic, but then heard and believed the gospel of Jesus Christ and subsequently left the Roman Catholic Church. It is hard to reach those who have been indoctrinated in the false teaching of Catholicism since childhood. But nothing is impossible for God. Our responsibility, as faithful ambassadors of Christ, is to make Him known and to share His life giving gospel of truth to our Catholic friends and family; Brethren, my heart's desire and my prayer for them is for their salvation.Maranatha!