What does 1 John 3:20 mean?

This verse provides the second half of John's statement, which began in verse 19. Here, the focus is on conviction of sin. The believer will be convicted when he or she does something wrong. Why? God lives in us through the Holy Spirit. The Spirit is "greater than our heart" and "knows everything." When we sin, the Spirit convicts us of the wrong and causes us to desire to change to live for God.

Further, this verse reminds us that God knows our motives, since He "knows everything." There is no hiding our feelings or sins from Him. Rather than this being a danger, the believer can take comfort that God lovingly understands our heart, good and bad. Yet, we also experience an uncomfortable self-judgment when we sin. In fact, true salvation results in a person being more sensitive to sin than they were before, since they experience conviction through the Holy Spirit.