How is it we know that we know Christ? By keeping his commandments. The word “keep” literally means “to look upon something as your treasure and therefore to guard it as your treasure.” Your attitude toward God’s commandments should be that they are your treasure. You carefully guard a treasure. That’s the attitude we ought to have when it comes to obeying the Word of God. What does it mean to keep God’s commandments? I think it means to keep them in two ways. First, the outward act is involved. Second, the inner attitude is involved. Those two things are always vital in the Christian life. When you live the Christian life, your outward conduct should flow from an attitude that characterizes your inner motivation. It is possible to obey and yet do it from an improper motivation in your heart. Jesus had a great deal to say about religious people who do outward acts with no inward reality to motivate those outward acts. Jesus called them hypocrites. “The heresy of all heresies of which teachers and Churches have been guilty, has been the thrusting of religious opinions and religious observances into greater prominence than moral purity. But beliefs unexceptionally orthodox are compatible with the life of devils, who believe and tremble.” B. H. Carroll was right on target when he said,
A mere verbal orthodoxy is hypocrisy, and is more hateful to God and more hateful to man than avowed infidelity. I am quite sure that a strict application of this test would empty thousands of pulpits, hundreds of professors’ chairs in Christian schools, and deplete thousands of church rolls. This emptying and depleting would not be deplorable but helpful. It would amount to a great revival.
Allen, David L. (2013-06-30). 1–3 John: Fellowship in God’s Family (Preaching the Word) (Kindle Locations 1053-1066). Crossway. Kindle Edition.