Its often easy to tell where people are from based on how they talk. John is making a very similar point in 1 John 2:3-8. Jesus makes a different kind of person. God teaches His children to think differently, talk differently, walk differently, react differently. It is tangible. It shows where they are from. John is making it clear that the greatest earthly blessing that human beings can experience is to be delivered from ourselves, and become a person who is quite unlike us. This is what God does. He calls us out of ourselves and into Him. And when this happens, He begins to perfect us in love. He brings us a superior life. He blesses us with better promises. He brings a better covenant. He calls us to live by better commands. To exist in this state is what it means to know Him and be in Him and to abide in Him – truly the love of God is perfected in him. By this we know that we are in Him – the love of God is being perfected.