God is light and in Him is no darkness at all. Because God is light, He contains the goodness we all long for. John urges us to take our sin seriously because it has the power to divide us, destroy us, and remove freedoms. By ignoring or tolerating our sin, self-deception, and chasing idols, we are walking towards darkness instead of the light. In Christ, we are fully excepted, significant, and eternally secure.