By this we know that we have come to know Him, if we keep His commandments. The one who says, “I have come to know Him,” and does not keep His commandments, is a liar, and the truth is not in him; but whoever keeps His word, in him the love of God has truly been perfected. By this we know that we are in Him: the one who says he abides in Him ought himself to walk in the same manner as He walked.
Our lives and actions reveal whether or not we really know Jesus. And what are His commandments? He said the greatest was to love the Lord with all our hearts, soul, and strength and to love our neighbors as ourselves. I imagine we all have room for improvement. But our lives should reveal that we are growing in the fruit of the Spirit and striving to walk as Christ would walk.
John blatantly calls any who would profess Christianity without “walking the walk” liars. Imagine if we (in love) held each other to this standard – the church as a body would look far different! Some might be offended and leave, but hopefully we would admit our shortcomings and strive to grow in Christ. There can be no true religion where one does not obey the law of God.
It is by keeping God’s commandments that his love is made perfect in us. The passage does not speak of sinless perfection but affirms that if true love exists in the heart it will manifest itself in obedience. A tree is known by its fruit. If we take seriously the commands of God and desire to keep them, we can be sure we know God. If we profess to be united with Christ, we must live our lives in the way that he would live our lives. Would he have the same priorities? Would he spend time on the things on which we spend time? How would your life change if you and Christ had a “Freaky Friday” experience and he controlled your body for a day?