Galater 3:24

"So that the law hath been (that is, hath turned out to be) our schoolmaster (or "tutor," literally, "pedagogue": this term, among the Greeks, meant a faithful servant entrusted with the care of the boy from childhood to puberty, to keep him from evil, physical and moral, and accompany him to his amusements and studies) to guide us unto Christ," with whom we are no longer "shut up" in bondage, but are freemen. "Children" (literally, infants) need such tutoring (Gal 4:3). might be--rather, "that we may be justified by faith"; which we could not be till Christ, the object of faith, had come. Meanwhile the law, by outwardly checking the sinful propensity which was constantly giving fresh proof of its refractoriness--as thus the consciousness of the power of the sinful principle became more vivid, and hence the sense of need both of forgiveness of sin and freedom from its bondage was awakened--the law became a "schoolmaster to guide us unto Christ" [NEANDER]. The moral law shows us what we ought to do, and so we learn our inability to do it. In the ceremonial law we seek, by animal sacrifices, to answer for our not having done it, but find dead victims no satisfaction for the sins of living men, and that outward purifying will not cleanse the soul; and that therefore we need an infinitely better Sacrifice, the antitype of all the legal sacrifices. Thus delivered up to the judicial law, we see how awful is the doom we deserve: thus the law at last leads us to Christ, with whom we find righteousness and peace. "Sin, sin! is the word heard again and again in the Old Testament. Had it not there for centuries rung in the ear, and fastened on the conscience, the joyful sound, "grace for grace," would not have been the watchword of the New Testament. This was the end of the whole…

The apostle in this chapter, I. Reproves the Galatians for their folly, in suffering themselves to be drawn away from the faith of the gospel, and endeavours, from several considerations, to impress them with a sense of it. II. He proves the doctrine which he had reproved them for departing from - that of justification by faith without the works of the law, 1. From the example of Abraham's justification. 2. From the nature and tenour of the law. 3. From the express testimony of the Old Testament; and, 4. From the stability of the covenant of God with Abraham. Lest any should hereupon say, "Wherefore then serveth the law?" he answers, (1.) It was added because of transgressions. (2.) It was given to convince the world of the necessity of a Saviour. (3.) It was designed as a schoolmaster, to bring us to Christ. And then he concludes the chapter by acquainting us with the privilege of Christians under the gospel state.

3:24 The law is like a child’s guardian (Greek paidagōgos, “tutor”). In Greco-Roman culture, a guardian was a faithful slave responsible for training and protecting the heir until he came of age.