When I read the works of men like James P. Boyce and Jonathan Edwards, I am amazed at the depth of their biblical knowledge and the keenness of their personal application. At the same time, I am astounded that these theological giants could justify the owning of slaves, support slavery as a system, and conform to the racial prejudice common in their day.

John Piper is right: “One of the central cadences of the gospel walk is the breaking down of ethnic hostilities and suspicions, and the impulse of unity and harmony” (Bloodlines, 175). So how is it possible to believe the gospel and articulate so clearly the doctrine of justification by faith alone, yet miss how this doctrine severs the root of racism and ethnocentrism forever? Even more, how can one’s life be so out of step with one’s theology? Here are some things to keep in mind as we seek to learn from the good and the bad we see in our fathers in the faith.

1. Do not separate belief from practice.

The one thing we cannot do is to explain away our theological forebears’ attitudes and actions by appealing to the historical context of their time. It’s true we must take into consideration their context in order to understand them and refrain from unnecessary vilification. But we must make sure that as we point out the general social ethics of the day we do not diminish the sinfulness of their practice. Otherwise, we run the risk of elevating right doctrine over right practice in a way that departs from the teaching of the apostles.

Attitudes and actions matter. When Paul confronted Peter for separating himself from the Gentiles, he wasn’t worried that Peter had abandoned justification as a doctrine. Paul called him out because Peter was denying the truth by his practice. In other words, we cannot paper over the sinful actions of our forefathers by appealing to the soundness of their doctrinal beliefs. And let’s be clear. Racial and ethnic superiority is antithetical to the doctrine upon which the church of Jesus Christ stands or falls.

2. Hold fast to the vertical and horizontal aspects of justification.

In Ephesians 2:8–10 Paul removes any ground for our boasting before God. Human mouths are machines of perpetual self-justification. The doctrine of justification by faith alone shuts down the machines. "Not from works, so that no one can boast!"

But notice next where Paul turns for the rest of Ephesians 2. The evidence of justification is the replacement of racial prejudice with the Spirit-filled temple of God: the church. “He is our peace, who made both groups one and tore down the dividing wall of hostility" (verses 11–22).

Do you see how Paul holds together both the horizontal and vertical aspects of justification?

The evil antithesis of justification vertically is self-righteous legalism: “I reach upward to God by my moral superiority.”

The evil antithesis of justification horizontally is self-righteous ethnocentrism: “I reach over others because of my ethnic superiority.”

But Paul will have none of this. The one true God will save his one sinful people in one simple way — through faith in Jesus the Messiah. (Romans 3:27–28)

3. Remember that justification by faith levels us all.

So what do we do with our heroes? For starters, we cannot stand smugly and chide our forefathers for their shortcomings. We would then ourselves be guilty of denying justification because we would be speaking from a place of moral superiority and chronological snobbery. Justification by faith alone kills the pride that comes from legalism, racism, pedigree, and yes, even chronology. We are no more righteous because of our time period than they were in theirs.

It also won’t do for us to abandon the theology of Edwards, Boyce and others simply because they were wrong on slavery. All theology must be measured by its fidelity to the truth of God’s Word, not by our ability to live up to God’s Word.

So what to do?

Instead of abandoning the biblical understanding of justification expressed eloquently through our heroes despite their flaws, we ought to lean harder into it.

Here’s the glorious truth: the reality they saw so clearly provides the answer to the sin they didn’t.

In other words, they discerned the reality of justification by faith alone better than they discerned the sinfulness in their own hearts and lives. And it’s that reality of justification by faith alone that levels us all and drives us to our knees — thankful for the clear example of horrendously flawed theologians articulating the only doctrine that gives hope to all of us who are horrendously flawed.

Slavery is a great evil, but even slavery cannot stand in the way of the grace and glory of the gospel. And just as we learn from the blind spots of the generations who have gone before us, we trust that the blood of Christ will cover our own blind spots. That’s why the more we walk with God, the more we cry like David: “Cleanse me from my hidden faults.”

It’s only in the security of being wrapped up in the righteousness of Christ that we can say, “Challenge me, Lord. Change me, Lord. Expose my wickedness.” And in the midst of it all, we cling to the hope that God’s grace is bigger than our biggest flaws.

Trevin Wax is the author of Holy Subversion and Counterfeit Gospels. He blogs daily at Kingdom People and serves as the managing editor of The Gospel Project for LifeWay Christian Resources.