2 My dear children, I write this to you so that you will not sin. But if anybody does sin, we have an advocate with the Father—Jesus Christ, the Righteous One. 2 He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world.
Love and Hatred for Fellow Believers
3 We know that we have come to know him if we keep his commands. 4 Whoever says, “I know him,” but does not do what he commands is a liar, and the truth is not in that person. 5 But if anyone obeys his word, love for God[a] is truly made complete in them. This is how we know we are in him: 6 Whoever claims to live in him must live as Jesus did.
It might be really to confuse these verses and think that anyone who messes up doesn't know God. After all John says, "Whoever says I know him but does not do what he commands is a liar and the truth is not in that person". Does that mean if we disobey one of God's commands we are a liar and don't know the truth?
This is where context means everything. John's first letter was a general letter to all Christians. It was written about 85-95 AD, so that the people he was writing were second and third generation Christians. John is trying to teach them good theology so they do not buy what the false teachers are selling. What was the lie they were pandering? They were saying that once you became a Christian, you are forgiven so obedience is not necessary. And, in fact, this led to new believers in Christ returning to previous immoral lifestyles.
But John teaches them that obedience is not because you are looking for God's approval, but because you have it. As we obey the new command Jesus gives us to love one another, we will have even more confidence because we experience the truth that sets us free. John says if we obey God, His love is truly complete in us. "Complete" is the same word in the Greek for maturity. To obey God is a sign of maturity, just as it as we grow up obeying our parents (well maybe most of the time). And the reality is as we trust that God's commands are really good for us and in our best interest, we come to know him in a deeper way.
Do you know God today? Do you want to know him more deeply and intimately? John says the key to this is obedience. Obedience sometimes has a bad connotation in certain circles. It is often associated with legalism and self righteousness. John gives us a huge challenge at the end of today's passage when he says, "whoever claims to live in him must live like Jesus did." How did Jesus live His life? In obedience to His Fsther, not to gain His approval but because He had it. Remember at His baptism the Father said, "this is my Son in whom I am well pleased". This was before Jesus really did anything.
We don't have to see obedience as a legalistic word. In fact by this we can be sure we know him, if we keep his commandments. This will show us God's love is being perfected in us, and also be a great witness to a watching world.