How do we know that we believe in Jesus? I've just read through 1 John, and it's like a 'how to know' manual. In his letter, John builds us a wall so that we can see which side of faith we're on.Light and darkness (1:6-7), truth and lies (1:8-10), love and hate (2:9-11) - they all land us on one side of the wall or the other. No straddling! No jumping from side to side either."We know that we have come to know him (Jesus) if we obey his commands" John writes. "The man who says, 'I know him,' but does not do what he commands is a liar, and the truth is not in him" (2:3).Harsh words! There are more of them too as you read on. Do we really want to know 'how to know'? If we look close, which side of the wall will we find ourselves on? I'm not always so sure.And that's just why John wrote the letter, not to shame and condemn but to show us, clearly, the right side of the wall. He reassures us that, though we may need to repent and sometimes deeply, we need not doubt or despair."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. He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world" (2:1-2). "This is love: not that we loved God, but that he loved us and sent his Son..." (4:10-11).John builds the wall to reassure us, and also to warn us."I do not write to you because you do not know the truth, but because you do know it...See that what you have heard from the beginning remains in you" (2:21, 24).Then and now, people claiming to know Jesus would tempt us over to the wrong side with lies and false teachings. To help us know and believe the truth about Jesus, John builds the wall with very compelling materials, his own testimony and those of the other apostles."That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked at and our hands have touched - this we proclaim concerning the Word of life" (1:1).John builds the wall with love, in Jesus. He wrote the letter wanting to "have fellowship" with all who read it (1:3), to make his "joy complete" (1:4). He calls them (and us) "Dear friends" (2:7).This love comes through so beautifully in 1 John 2:12-14 (check it out). My Bible note says that John extends these verses with repetition to assure his readers that despite the rigorous tests of faith that he puts them through in the letter, he has confidence in their salvation."How great is the love the Father has lavished on us, that we should be called children of God! And that is what we are!" (3:1).How do we know what love is? Now that we have this reassurance that "Jesus Christ laid down his life for us", John writes, we "ought to lay down our lives" for others (3:16).