And by this we know that we have come to know him, if we keep his commandments. – 1 John 2:3 ESV
The knowledge of God is far more than an academic or cognitive kind of knowledge. You can know details and even personal information about the Prime Minister of England or the President of the United States, but that doesn't mean you know them. You simply know something about them. You have no personal knowledge of them and cannot claim to have a close relationship with them. Sadly, this describes the relationship that many have who claim to know God. Their knowledge is Book-knowledge, fed to them from the pulpit or Sunday School classroom, or passed on to them by their parents. If you were to ask them if they know God, they would say, “Of course, I know Him.” They could probably tell you facts and details about God, concerning His character, His creation of the world, His miracles recorded in the Bible, and even His offer of salvation made available through belief in His Son. But according to the apostle John, the proof of their knowledge of God would be far more simple and conclusive. “And by this we know that we have come to know him, if we keep his commandments” (1 John 2:3 ESV). In other words, obedience is the true test of our knowledge of God. But we must be careful here. John is not telling us that obedience is the way to come to know God. He is not saying that you have to obey God in order to know Him. No, John is telling us that obedience is a proof of our knowledge of God. It is how we can know that we truly do know Him. The kind of knowledge John speaks of is intimate and experiential, not academic. He uses the Greek word, ginōskō, which was a Jewish idiom referring to sexual intercourse between a man and a woman. This isn't some kind of a head-knowledge. It is an intimate awareness of God's involvement in one's life. Because the only way we can keep His commandments is IF we know Him. It is His power, made available to us through the presence of His Spirit, that makes it possible for us to live in obedience to His will. It is our relationship with God's Son, Jesus Christ, that makes a life of obedience, a life of righteousness, possible. So when John states, “whoever says he abides in him [Christ], ought to walk in the same way in which he [Christ] walked” (1 John 3:6 ESV), We can and should live our lives as Jesus lived His – humbly, sacrificially, and in complete obedience to the Father's will. No, we cannot live our lives completely without sin, as He did, but we can live in obedience. Because we know God, we can put to death the deeds of the flesh (Romans 8:13). Paul tells us, “So put to death the sinful, earthly things lurking within you. Have nothing to do with sexual immorality, impurity, lust, and evil desires” (Colossians 3:5 NLT). We can live differently and distinctively. We can say yes to God and no to sin. Again, Paul writes, “Do not let any part of your body become an instrument of evil to serve sin. Instead, give yourselves completely to God, for you were dead, but now you have new life. So use your whole body as an instrument to do what is right for the glory of God” (Romans 6:13 NLT).
We can know that we know God, that we have a relationship with Him, when we see the remarkable change take place in our character that is only possible through the redemptive work of His Son. When we come to know Christ as our Savior, we receive a new nature, a new capacity to live in obedience to the will of God. He sets us free from slavery to sin and provides us with the freedom to live in willing obedience to God. “When you were slaves to sin, you were free from the obligation to do right. And what was the result? You are now ashamed of the things you used to do, things that end in eternal doom. But now you are free from the power of sin and have become slaves of God. Now you do those things that lead to holiness and result in eternal life” (Romans 6:20-22 NLT). When we obey God, we don't get the credit, He does. What we get is the assurance that we know Him. “My old self has been crucified with Christ. It is no longer I who live, but Christ lives in me. So I live in this earthly body by trusting in the Son of God, who loved me and gave himself for me” (Galatians 2:20 NLT). I know Him. He knows me. Not only that, He loves me. And He empowers me to live righteously, even when surrounded by unrighteousness. He has given me His Spirit to help me do battle with my own sin nature. I don't have to give in to sinful desires. I don't have to fall for every temptation that comes my way. I can walk like Jesus walked. And when I do, I can know beyond a shadow of a doubt that I know God. Over in his gospel, John recorded a fascinating statement from the lips of Jesus. It was part of His prayer that He prayed to the Father not long before His trials and crucifixion. Jesus said, “And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent” (John 17:3 ESV). Eternal life is NOT simply heaven. It is not an opulent residence reserved for us somewhere in the future. It is the knowledge of God and His Son. It is a relationship with the Creator of the Universe and the King of kings and Lord of lords. And I can know that I know them because I can see their life-transforming power at work in my life – right here, right now. And THAT is eternal life.