An example of the importance of the doctrine of justification in church history is the historical debate between Pelagius (360-420), a British monk, and Augustine (354-430), the Bishop of Hippo. Pelagius taught that salvation was achieved through obedience to God's divine commands. In opposition to this, Augustine maintained the Scriptural truth that sinners are unable to save themselves by their own works and are reliant solely upon the grace of God for salvation. According to Augustine, since works are unable to save, grace alone must save, and that grace is apprehended only through faith.
Augustine wrote:
"You may proclaim that ancient just men possessed ever such great virtue, yet nothing saved them except faith in the Mediator, who shed His blood for the remission of sins."
[Src: Ad Bonifactum Book 1, Chapter 21, cited in Martin Chemnitz, Examination of the Council of Trent, vol. 1, trans. Fred Kramer (St. Louis: Concordia Publishing House, 1971), p. 506.]
Thus, Augustine championed the New Testament church's doctrine of justification by grace through faith apart from works.
For this reason, many have suggested that Augustine laid the necessary groundwork for the debates that would later grip the church in the sixteenth century. It is no coincidence that Martin Luther was originally an Augustinian monk (a monastic order dedicated to upholding the teachings of Augustine). Yet in the early 1500s, Luther began to recognize that the church had greatly deviated not only from Augustine's doctrine of justification but also from the Scriptural doctrine of justification by making works a meritorious cause of salvation.
While the Reformation initially began as a protest (hence, Protestantism) against the selling of indulgences (documents promising forgiveness of the temporal punishments due to venial sin) the Protestant reformers (Luther, Calvin, and others) eventually came to challenge the entire Romanist doctrine of salvation by faith and works, constitutive traditionalism, etc. The Reformers saw these as a revival of the Judaizing tendencies opposed by the apostles and the works-righteousness opposed by Augustine and many other ancient church fathers.
Though Rome taught the necessity of Christ, it denied that Our Lord's death was sufficient, without human cooperation, to save sinners. The Reformation solas, among which sola fide is central, therefore speak not only to the necessity of Christ, grace, faith, and Scripture, but to the sufficiency of the same.
Sadly, one of the greatest challenges facing the church today is its re-evangelization. While many evangelicals may understand the doctrine of sola fide—that we must place our faith in Christ to be saved—it seems many have abandoned the Scriptural concept of sola gratia (grace alone). The synergistic conception of sola fide—faith arises out of an inherent capacity of the natural man—therefore must, by definition, draw on nature to cooperate with God's grace as the human fulfillment of a condition.
Why do many sincere Christians believe this? I speculate that it is because by nature some want to maintain an island of righteousness—a last bastion of pride in thinking that they can still contribute something, be it ever so small—to their own salvation. It would involve great humility on everyone's part to admit this to be so. If churches took more efforts to search the Scriptures and reform their doctrine on this single point, I am convinced that a great deal of blessing would be restored and God would remove much of the current worldliness in our midst.
AMR