1 John 2:18

1 John 2:18 says, Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.  John once again addresses little children, but this applies to all followers of Christ, no matter how old they may be.  He said they had heard that the antichrist would come in the last days, and then said there were already many antichrists, and because of this, they could know they were in the last days.  Since the beginning of the church, those who have accepted Jesus Christ as their Savior and Lord, people have believed that they were in the last age, and this is true.  It doesn't matter if His return happens in our lifetime or not, it is always near and we should live as though we believe that.   

Verse nineteen adds, They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us: but they went out, that they might be made manifest that they were not all of us.  John said that some who had professed to be Christians had left the church, because the never were believers to start with.  John said they made it clear that they weren't part of the church, by their actions I believe.  Not everyone who professes to be a follower of Christ is, and their actions will prove this.  I don't believe that this means a Christian who sins again, but those who live guided by sinful actions every day without seeing this as being wrong.   

Verse twenty continues, But ye have an unction from the Holy One, and ye know all things.  John said that the followers of Christ had a spiritual knowledge that comes from God and allows them to know all things that they should do.  We as Christians may not understand everything about the world, but we should know everything that we need to know to follow God faithfully. 

Verse twenty-one concludes, I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.  John said he hadn't written to them because they didn't know the truth of God but because they did.  He added that there was no lie in the truth of God.  If we are a follower of Christ, then we know His truth and we need to live by faith in that truth.