Martin Luther published his edited lectures on Galatians in 1519. In these lectures, we may examine Dr. Luther’s new understanding of justification by faith alone in Christ’s promises. When he commented on Galatians 2:16-21, Luther discussed the difference between divine and human righteousness.
First, he identified an external manner of righteousness that results from an individual’s own powers and rests on the performance of the Law. Luther equated this external way to the scholastic teaching on the achievement of righteousness through the dutiful practice of just deeds by obeying the Law.
In contrast to this, sinners receive righteousness the inward way by grace through faith in Christ’s Word. This begins with the complete hopelessness of one’s own righteousness like the tax collector who prayed humbly for God’s mercy and was justified before God (Luke 18:13-14). Luther equated this calling upon God with this true, Christian righteousness. Thereby, they become the children of God who gladly do fulfill the Law through faith and love.
Sinners do not become righteous by doing righteous deeds, but rather those who call upon the name of God by faith in Christ fulfill the law of love through the power of God’s Spirit. Thus, Luther reiterated his rejection of the application of Aristotle’s philosophy of ethics to theological doctrine. (See “Martin Luther Against Scholastic Theology”)
Finally, Luther contrasted this proper Christian righteousness with the external, human righteousness as he concluded:
“Thus it is clear that Christian righteousness and human righteousness are not only altogether different but are even opposed to each other, because the latter comes from works, while works come from the former. No wonder…that Paul’s theology vanished entirely and could not be understood after Christians began to be instructed by men who declared falsely that Aristotle’s ethics are entirely in accord with the doctrine of Christ and of Paul, by men who failed completely to understand either Aristotle or Christ. For our righteousness looks down from heaven and descends to us. But those godless men have presumed to ascend into heaven by means of their righteousness and from there to bring the truth which has arisen among us from the earth.” LW 27: 225.
Dr. Luther here reversed the monastic idea of the ascent of the soul to God through prayer and mystical contemplation. Martin the Observant Augustinian Friar had practiced this type of life for many years. With the emergence of the proper understanding of justification, Luther reverses the notion of ascent and reorients the focus toward Christ’s descent through the Incarnation. Notice how he used a common phrase associated with medieval mysticism, inward way, but reversed its meaning. It’s no longer about the Christian’s inward striving or outward works, but Christ’s work for the Christian and in the Christian by faith.