I John 2:5 ~ The Amplified Bible
But he who keeps (treasures) His Word [who bears in mind His precepts, who observes His message in its entirety], truly in him has the love of and for God been perfected (completed, reached maturity). By this we may perceive (know, recognize, and be sure) that we are in Him.
John teaches us a lesson. We understand this lesson (hopefully) in regards to loving one another. If a friend or family member tells you that they love you but treats you otherwise, you don't really believe they love you. One of my Mom's favorite quotes when I was a kids was, “actions speak louder than words”. It's a great one and bears repeating. We see in this passage of scripture that our obedience shows our love for Him. If we say we love God but ignore His direction and constantly do things that are displeasing, do we really love Him? Obedience matters. Let's walk in His Word today, by His grace and strength. Let's walk in love.