If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth (1John 1:6). And why is that? Check the context. Because God is light (v 5) and how can anyone have fellowship with the light when he walks in darkness (sin)? So simple, yet how many don't seem to realize what they are doing?
If we say we have not sinned, we make him a liar, and his word is not in us (1John 1:10). This one seems a little confusing after the first one. First he says we shouldn't sin, then he says we shouldn't claim not to sin. How is that supposed to work? It's not really that difficult. Remember what we said God was? He is light, and light exposes the darkness. So what do we do when that darkness is exposed? Do we keep walking in it, or do we "confess our sins" (v 9)? It is the one who does not confess his sins when they are pointed out who is the liar. Nor the one who says he has never sinned in the first place.
Whoever says “I know him” but does not keep his commandments is a liar, and the truth is not in him (1John 2:4). Many of these things have similar verses in John's gospel. What does Jesus say about himself in John 14? "I am the way, the truth, and the life." If Jesus is the truth, then his commands are truth too. If we do not obey him, then the truth is not in us and that certainly makes us the opposite of truth, or liars.
Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son (1John 2:22). This is a handy verse to have in your hip pocket when someone starts going on about the Antichrist as if it were some superhuman demon who might attack us, especially in that person's views of a millennial kingdom. Look at John's words: Anyone who says Jesus is not the Christ is an antichrist. Period. I can think of a few religious groups that fit that mold easily, and a few of my neighbors too. It's not some mystic apparition—it's people, and they are liars, John says.
If anyone says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen (1John 4:20). This one ought to stop us in our tracks. And why is that? Because none of us would ever say out loud, "I hate my brother," but in the next moment we might sneer at them, gossip about them or slander them, look down our noses at them, or take an "us" and "them" attitude (I have heard preachers do this!) in a way that belies our words. When we do anything like that, we are liars. And remember this: this man who is calling people liars is often called "the apostle of love." Don't ever think that love means you don't correct the fallen.
See how many lessons we can find by simply counting words? This one ought to keep a class teacher or preacher busy for a few weeks itself!
Sometimes beginning things like this is difficult when it is new. Can I help you get started with a few "assignments?" Try finding all the places where John tells us what is involved in fellowship. Find the places where he tells us why he wrote the epistle in the first place. If you want to stay busy for a good while, look up all the times "love" is used and divide it into the object of that "love"—who or what it is that we should love. Once you get started, it should come more easily, and, if I know my readers like I think I do, you will be hooked on the fact that you can learn all by yourself with just a little effort.
Whoever believes in the Son of God has the testimony in himself. Whoever does not believe God has made him a liar, because he has not believed in the testimony that God has borne concerning his Son (1John 5:10).
Dene Ward