"Keeping a Pure Heart"

It is not surprising to me anymore how God makes me travel in circles; neither do I wonder what He will show me next, because I have grown interested in being surprised. When we are talking about a pure heart, it does not mean that we have a heart which has not sinned, but rather a heart that has no sin. The watchmen that went about the city and the keepers of the walls from the verses that I closed with yesterday are the ones whom we must fear, because that is the poison which can make us hold onto sin. What is sin? missing the mark is the best definition of what sin has become, and the mark can be missed in our relationships also. To be better equip to not miss the mark, an archer will practice hitting the mark over and over, that is called archery; which is what is required for one to become skilled enough to be called an archer. In our relationships, the point is the same; to be better equip to not miss the mark, we must practice hitting the mark over and over; and in love, that is how you are declared lover, (sounds dirty?). But really; hitting the mark every time will most likely not happen, which is referred to as sin; and when sin does happen there are consequences, sometimes minor, sometimes major, but most assuredly there are consequences. However, with God there is forgiveness of sin, to the point of forgotten; however not so easy for us, because we tend to hold onto and keep track of our misses; that is where the 'watchmen' and the 'keepers of the walls' come into play, because they continue to yell out, Sinner, as we try to correct our way. Two different sources are given here, although they both do the same function, which is to guard the city from intruders; or better defined for the purpose of this post: to declare sin and trespass by exposing it, in an effort to cause harm or attention to the sinner. These two sources are different because of their locations; one is upon the walls, looking for those that might be coming in; while the other is located within, roaming the city and looking for intruders. I have tried to determine which is which, but I am a little confused on how the enemy can get into the city, let alone become a watchmen within it; however, the way I see it, and in the context of what we are talking about, the one upon the walls is our conscience, and the watcher is the devil... "My little children, let us not love in word, neither in tongue; but in deed and in truth. And hereby we know that we are of the truth, and shall assure our hearts before Him. For if our heart condemn us, God is greater than our heart, and knoweth all things. Beloved, if our heart condemn us not, then have we confidence toward God. And whatsoever we ask, we receive of Him, because we keep His commandments, and do those things that are pleasing in His sight. And this is the commandment, That we should believe on the name of His Son Jesus Christ, and love one another as He gave us commandment." (1 John 3:18-23)