For all the mystery surrounding the first letter of John (who wrote it, to whom did they write it, when did they write it, etc.), I have found it to be an early treatise on Christian ethics.
I John states, “Whoever says, ‘I abide in him (Christ),’ ought to walk just as he walked” (2:6). Of course, we ought to hear echoes of the Old Testament here. The psalmist says “Your word is a lamp to my feet and a light to my path” (Psalm 119:105). Notice that these images are not passive. We aren’t told to think like Christ thought, or study like Christ studied, but we should actively engage in behaviors and attitudes that are congruous with Christ.
Watching a child learn how to walk is much like watching a Christian learn how to live. At first, our muscles aren’t strong enough, our sense of balance isn’t developed, and we need a hand to help us take our first steps. Eventually we learn how to walk, even how to run and skip. Sure, we may trip up along the way – but that doesn’t mean that we should give up walking. The same with a holy life – sure, sin is going to trip us up, but that doesn’t mean that we ought to give up trying.