"You therefore must be perfect, as your heavenly Father is perfect." - Matthew 5:48
I level everything in our house. We have a wide variety of levels to do the job right, even a small pocket level if I'm on the run. The principle is simple... you move the object or adjust one side or the other until the little bubble falls in the very center. If you want something straight, you never go by eye; you need a level.
Jesus gives thorough counsel on the depth and demand of Biblical living. He knows that many people will make a concerted effort and be satisfied if they are just a little better than the next person. So, He provides a divine reference point for Biblical living... our Heavenly Father. If you want to live Biblically you can't do it by eye, you need a Level.
When you stop and take inventory my friend, how does your Biblical living appear? Do you pat yourself on the back because you're doing way better than that Deacon or the Preacher? Jesus never said be perfect (or "mature" or "complete") like your friend or Christian leader. We don't ever need to go by eye when we have our heavenly Father as our Level.