Like a single tree trunk separates into various large branches, Christianity can be divided into several large family groups. The largest are Catholicism, Orthodoxy and Protestantism. Most Americans have at least a passing familiarity with Catholic and Protestant churches. Very few churches identify themselves outwardly as Protestant, but many stem from the Protestant branch of Christianity. The Protestant faiths include Presbyterianism, Episcopalianism, Lutheranism, Methodism and a number of other denominations. All churches which trace their beginnings to the Protestant Reformation are Protestant churches.
Some of these churches, like many Baptist churches, look and act nothing like the Catholic church. Some, like many Lutheran churches, bear an outward resemblance to the Catholic church. Is there any real difference between the Catholic church and Protestant churches?
This question is complicated by the many variations of beliefs in individual churches, even within the same denomination. These differences are almost beyond counting and vary from congregation to congregation. Some of the differences are very significant and some are unimportant. To keep things short, this answer will focus on the official doctrines that have traditionally separated Catholics from Protestants.
One further complication is the many Protestant groups who downplay, deny or ignore the official church doctrines. This branch of Protestantism, called theological liberalism, gives little concern to the doctrinal creeds of the churches. Liberalism emphasizes social issues and holds very different opinions from the Catholic church on matters of sexuality, abortion and the role of women in the church.
Traditional Protestants and Catholics have many important beliefs in common. They all believe there is only one God who is a Trinity. They believe Jesus is God the Son who became man to die for the sins of humanity. They believe the Bible is the Word of God given by the Holy Spirit through the apostles and prophets. They believe people are sinners in need of a Savior. Despite these very important beliefs in common, the differences that separate the two groups are equally as important.
The Protestant reformation began with the statement, “Now the just shall live by faith.” (Galatians 3:11) The doctrine of salvation by faith alone is the biggest and most important difference between Catholicism and Protestantism. The Catholic church teaches that through faith the person is enabled by Christ to accomplish salvation. Protestant churches teach that salvation is fully accomplished by Christ and given to the one who receives Him by faith. These two beliefs are not compatible with one another. The one says works are essential to salvation, the other says any one attempt to work for salvation are not saved.
There are many, many other differences between Protestantism and Catholicism. However, what truly sets these two groups apart is their different teachings on salvation. How a person receives forgiveness of sin and salvation is a matter of the greatest importance. As long as the churches teach a different way of salvation there will always be a divide between Catholicism and Protestantism.