What were the Galatian believers turning back to, and what does that reveal about the law?
The Galatian believers were turning back to weak and beggarly things, specifically legalism and observance of days, months, times, and years. From man's standpoint the law was weak and beggarly because it had no power to help people keep its demands, though from God's standpoint it was perfect and righteous.
Les explains that these Galatian believers were turning back to the weak and beggarly things, going back under legalism. He notes that from God's point of view the law was perfect, absolute, and righteous, but from man's point of view it was weak and beggarly because it had no power to help people keep it. Paul points to their observance of days, months, times, and years, practices associated with pagans and Israel's economy. The law could not empower obedience; the gospel is empowered by the Holy Spirit, who sets believers in the right direction, so they do not need the law and are not under it, because the Spirit takes up where the law leaves off.