“Only believe, only believe,” says an old evangelistic hymn by Paul Rader. Then the hymn paraphrases the angel's words to Mary prior to Jesus' conception, “with God nothing shall be impossible.” The hymn's words reflect the five principles, or the “five solas” of the Protestant Reformation: Sola Scriptura, Solus Christus, Sola Gratia, Sola Fide, and Soli Deo Gloria; which translate to: Only Scripture, Only Christ, Only Grace, Only Faith, and Glory Only to God.

Sola Fide, only faith, is a core teaching that all Protestants traditionally affirm. The reformers, stung by corruption in the church (especially in the sale of indulgences), used this teaching to highlight that the only thing efficacious for salvation is faith. Works of the law, whether of the Old Testament or the rules of the church, are not enough.

The proponents of Sola Fide didn't want to discount works of the law (being moral, for example), or imply that obedience to Christ (a form of keeping the law) wasn't necessary, but the law was not the means of salvation. Again, faith through grace from God (the “free gift,” to use a favorite redundancy of evangelists) is the sole efficacious way of salvation.

Fundamentals Only

Many preachers and teachers have, however, taught that everything beyond “only faith” can actually get in the way of salvation. At this point they part company with most Catholics, Orthodox, and more traditional Protestants, including most contemporary evangelicals.

Many call this emphasis on belief “fundamentalism,” which means, in this case, “fundamentals only.” Jesus certainly taught much more than “only believe,” as did the apostles and the church from its beginning, though believing is the necessary first step toward getting on the way to salvation.

Once Saved, Always Saved

Many Protestants, like Luther, Calvin, and Zwingli especially, have taught that salvation is a once-and-for-all event (some calling it “once saved, always saved” or “the security of the believers”). However, even most of the people who believe salvation is a onetime event have allowed that a person can be misled to think he or she has been saved, only to fall back into sin again later (or seem to fall back, if the person was never saved in the first place) and, in some cases, be saved again, this time for real.

Catholics, Orthodox, and Wesleyans (followers of the teachings of the great Protestant revivalist John Wesley), emphasizing Jesus' repeated words, “he who endures to the end shall be saved,” generally teach that calling oneself saved is presumptuous. Orthodox writers like to put it, “I have been saved; I am being saved, and, God willing, I will be saved,” referring to the need to “endure,” or, as Calvin famously rendered that word, “persevere.”