What does John 1:17 mean?

This explains an important difference between the ministries of Moses and Jesus. Moses' ministry brought knowledge of the law. But the law could only show us how sinful and broken we were (Romans 3:20). It was never intended as the final means of our salvation (Jeremiah 31:31–34; Hebrews 9:24).

Rather than only bringing truth, Jesus also brought us grace. Instead of simply telling us we were broken, Christ gave us a way to fix what was wrong. This is an important, common theme of the Bible. Human efforts will always fall short, and everyone is corrupted with sin (Romans 3:23). Instead of leaving us to face that uncomfortable truth alone, Jesus provided a way for us to experience forgiveness (Hebrews 4:15–16). Merely doing good deeds can never save us, only God's grace, through faith, can do that (Titus 3:5; Romans 11:6).

This is further represented using miracles. In the first plague against Egypt, Moses turned water into blood, which is symbolic of judgment (Exodus 7:20). Later, only those homes which had the blood of a lamb on their doors were "passed over" by God's wrath (Exodus 12:26–28). Jesus' first miracle was turning water into wine—symbolic of blood—as a gracious gift (John 2:7–11). Only those who accept Christ's sacrifice of blood are spared from the judgment we all deserve (1 John 1:7; John 3:36).