What does Galatians 3:19 mean?
This is a complicated and important verse in Galatians. Paul has been building a strong case for why the law cannot save us from our sin (Galatians 3:10–12). Instead, he teaches that God has always intended Christ to be the ultimate means of our salvation (Galatians 3:13–14). Now he asks the obvious question: "Why then the law?" In other words, what's the point? Why did God create and implement this complex collection of rules and regulations for His people Israel?Paul's answer is that the law was added "because of transgressions." This is from the Greek word parabaseōn, a word which can mean "breaks, violations, breaches," or more simply as "sins." One purpose of the law may have been to show the Israelites what actions were sinful so they could avoid them. God, in His grace, gave them the law to show His own standards for their right and wrong behavior.
Paul may also mean something else by the phrase "because of transgressions," however. It's true that the law showed the Israelites God's standard for right and wrong. More than that, though, the law showed the Israelites that they wanted to do what was wrong and were unable to obey God's standard perfectly. Or, as Paul put it in Romans 5:20, "the law came to increase the trespass." God instituted the law, in part, to show the Israelites, and all of us, just how sinful we really are. Only sinful people know they need to be saved from their sin; the law convinces us of how much sin we have to be saved from.
In addition, Paul writes that the law was always meant to be temporary. It was added for God's people 430 years after God's promise to Abraham and his offspring (Galatians 3:17) and only meant to be applied until that one, specific offspring, Jesus, showed up to receive the promise as Abraham's ultimate descendant (Galatians 3:16).
Paul also says the law was put in place "through angels by an intermediary." This phrase can also be confusing, and is explained in better detail by Paul in the following verse.