What does 1 John 2:11 mean?
Verses 9–10 described how those who show hate for Christians lack fellowship with Christ. Verse 11 completes this thought with more clear, direct language. Hate for others is totally incompatible with fellowship in Christ. Saved believers are capable of such a sin, but those who do so demonstrate serious spiritual sickness.The idea of "walking in darkness" is often associated with evil or sin. This is not the same as "stumbling," or "falling," which implies a temporary situation. There is a difference between stumbling briefly into darkness and "walking" in darkness as a matter of habit. The person who walks in darkness is in a position of grievous spiritual danger. They have no clear vision or purpose, simply because without light they cannot see. Darkness is blinding.
In other words, hatred of others is a sin which prevents a person from being able to truly follow Christ. Though darkness is powerful, the Gospel of John declares: "The light shines in the darkness, and the darkness has not overcome it" (John 1:5). God's love is far more powerful than the sin of this world.