Saint Augustine of Hippo was a great church leader of the fourth century. But as a young man before his conversion to Christianity, Augustine struggled with God and with the temptation to sin. He tried to live a morally upright life in his own strength, but he would inevitably fail.

In his autobiography, The Confessions, he wrote that on one occasion he felt so much guilt, shame, and condemnation for his sins that he flung himself down under a fig tree and wept a flood of tears. “God, why can’t I live a righteous life?” he prayed. “I want to stop sinning, but I can’t!”

Just then, he heard a child, chanting in a sing-song voice, “Take up and read, take up and read!” He interpreted those words as a message from God. But what did the message mean—“take up and read?” Read what? Then Augustine remembered the scroll he had left with his friend, Alypius—a scroll of Paul’s letter to the Christians at Rome.

Augustine jumped up, went to his friend, and found the scroll. He decided to read the first passage his eyes fell upon:

Let us behave decently, as in the daytime, not in orgies and drunkenness, not in sexual immorality and debauchery, not in dissension and jealousy. Rather, clothe yourselves with the Lord Jesus Christ, and do not think about how to gratify the desires of the sinful nature (Romans 13:13-14).

Instantly, a sense of peace came over him. His struggle with God was over. Though he could not resist temptation in his own power, he could “clothe [himself] with the Lord Jesus Christ” and allow the Lord to live through him. At that moment, Augustine was a changed man. His transformation had begun with two sentences from the book of Romans.

Paul’s letter to the Romans is his greatest. In fact, I believe it is the most powerful document ever written. Of all the New Testament letters, Romans is the broadest in scope and deepest in insight. No other document has affected and transformed more human lives. Here are just a few stories of lives it has changed:

Eleven centuries after St. Augustine, a German theologian named Martin Luther was meditating on this great phrase from Romans 1:17: “The righteous will live by faith.” As he contemplated those words, Luther realized that he had completely missed the point of the Christian gospel! True Christianity is not a matter of rites and rituals and ceremonies. The essence of Christianity is faith, not works! Those words from the book of Romans lit a fire in Luther’s soul, a fire that would become the great Protestant Reformation.

Of all the New Testament letters, Romans is the broadest in scope and deepest in insight.

The seventeenth-century Puritan preacher John Bunyan spent twelve years in jail in Bedford, England. His crime? He left the Church of England and sought to worship God according to his own conscience. While studying Romans in his jail cell, Bunyan was inspired by the themes of Romans to write an allegorical novel, The Pilgrim’s Progress. Today, that novel—which illustrates how Christians should relate to God and the world around them—is still a widely read classic.

Another whose life was transformed by the message of Romans was a young Anglican minister, John Wesley. In 1735, Wesley went to America, where he had served a brief stint as a pastor to British colonists in Savannah, Georgia. There he was spurned by the woman he loved and rejected by his congregation. He returned to England in February 1738, embittered and dejected, feeling like a complete failure.

For the next few weeks, Wesley tried to live a righteous life, but he continually battled temptation. “I was indeed fighting continually, but not conquering,” he later recalled. “I fell and rose, and fell again.” During this time, he often doubted God and his own faith.

On May 14 of that year, Wesley went to a meeting on Aldersgate Street in London. There, a man was reading to the congregation from Martin Luther’s preface to the book of Romans. Wesley wrote in his journal that as he listened, “I felt my heart strangely warmed. I felt I did trust in Christ alone for salvation.”

As a result of his encounter with the book of Romans, John Wesley’s life was transformed. He became one of the leaders of the Great Evangelical Awakening that brought thousands of people to faith in Jesus Christ.

That is the power of this amazing book. Embedded in the pages of Paul’s letter to the Romans is the power to change individual lives and entire societies. It is a power that we all long to experience as followers of Jesus Christ.

Adapted from Joy of Living Bible Studies: Romans, commentary by Ray C. Stedman. Order the full study here.