What is the context?
Paul now asks the question raised by his defense of the promise: why was the law given? He says it was added because of transgressions, until the promised seed came. Its role belongs within the story leading to Christ.
He describes the law as administered through angels by a mediator, someone acting between parties, then points out that a mediator involves more than one party while God is one. The brief statement sits within his comparison of the law with God’s promise.
He directly rejects the idea that the law opposes God’s promises. The law cannot impart life. Scripture confines everything under sin so that the promise through faith in Jesus Christ may be given to those who believe.
Paul then pictures life under the law as a time of custody. The word translated guardian is παιδαγωγός, paidagōgos (pie-dah-go-GOSS), a child’s guide or guardian. Thayer’s lexicon explains that sense of supervision and applies it to the law preparing people for Christ.
His point concerns the change Christ brings. The law’s guardianship led toward being justified by faith. Now that faith has come, he says they are no longer under that guardian.
How is this passage commonly understood?
Christians commonly understand the law as exposing sin and preparing for Christ, while being unable to give the life He brings. The Catholic Catechism, paragraphs 1963–1964, explicitly uses the guardian picture: the law shows what is needed and prepares people for the Savior, while the grace of the Spirit supplies the strength it cannot itself give.
One common reading of the brief mediator statement contrasts the law’s mediated delivery with God’s direct promise. Wesley’s note on verse 20 and the USCCB notes on verses 19–20 both explain the contrast in that direction.
Christians differ in how they describe the law’s continuing place in life with Christ. The Reformed Westminster Confession, chapter 19, distinguishes ceremonies fulfilled in Christ from moral commands that continue to guide believers. Dallas Theological Seminary, article V, describes the Mosaic law and the present rule of grace as distinct periods with different responsibilities. Its statement also insists that salvation has always been by grace through faith. Both statements distinguish God’s instruction for His people from trying to earn salvation.
Where does this fit in God's plan?
Luke 24:44–47 records Jesus explaining that the Law of Moses, the Prophets and the Psalms find their fulfillment in Him. His suffering and resurrection lead to the proclamation of repentance and forgiveness in His name to all nations.
That explicit account places the law within God’s larger saving story. Its place is understood in relation to the Christ it points toward and the life and forgiveness being proclaimed through Him.
What is our position?
We don't have a position on this passage yet. When our study reaches a conclusion the text supports, it will appear here.