1 John 2:1

"My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defense - Jesus Christ, the Righteous One." NIV translation

John gets right to it in this verse by telling us his purpose for this section of his letter. The simple purpose is so that Christians will not sin but he also makes it clear that we do not lose our salvation. This chapter is addressed to "My dear children" which would lead us to believe that it was to those that he led in the faith (pastored).

1 John 2:2

"He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world." NIV translation

He reminds us that because Jesus is righteous and paid for us, we are saved and so we do not have to worry about whether His sacrifice was sufficient. This speaks of God's love for us in that He sent His Son to be the sacrifice for our sins.

1 John 2:3 & 4

"We know that we have come to know him if we obey his commands. The man who says, 'I know him,' but does not do what he commands is a liar, and the truth is not in him." NIV translation

This passage speaks to us about our love for Jesus. This may seem harsh but what John is saying is that, if we know and love Jesus, it will be demonstrated by our actions. He is talking about a pattern of ignoring Jesus' commands and not an occasional sin as he already said that the sins are paid for by the sacrifice of Jesus. He also makes it clear that there really is no "gray area"; we know and love Jesus or we are children of the devil. He says that we are liars (children of the father of lies which is Satan) if we do not love Jesus enough to be obedient.