17 But if you call yourself a Jew and rely on the law and boast in God 18 and know his will and approve what is excellent, because you are instructed from the law; 19 and if you are sure that you yourself are a guide to the blind, a light to those who are in darkness, 20 an instructor of the foolish, a teacher of children, having in the law the embodiment of knowledge and truth— 21 you then who teach others, do you not teach yourself? While you preach against stealing, do you steal? 22 You who say that one must not commit adultery, do you commit adultery? You who abhor idols, do you rob temples? 23 You who boast in the law dishonor God by breaking the law. 24 For, as it is written, “The name of God is blasphemed among the Gentiles because of you.”
There is such a thing as having a head knowledge of the Word of God and not a heart knowledge. It is possible to honor God with your lips, but have a heart that is far from him. This was the situation with the Jews in general and the religious leaders in particular. They knew the letter of the Law. They could quote it to you forwards and backwards. They made every effort to display themselves as righteous as they held to every jot and tittle of the Law.
Despite their efforts of obedience they lacked the one thing that made all their effort worthless, they lacked faith. They lacked a faith and trust in God that made the Law a joy instead of a burden. They lacked the trust in the grace and mercy of God’s salvation apart from the Law. They lacked a true heart for God.
Our hearts are no different. We can easily find ourselves drifting into a life that becomes filled with “rituals” from our knowledge of God, but we no longer have a heart for God. This is a danger we all face. John Piper explains this potential problem and the solution in this way:
Now here is the warning and the gospel invitation – mainly for me, but also for you. Let us be careful – O so watchful and careful – all of us lovers of the Bible. Beware lest we rest in the Word and boast in God and know his will and approve what is excellent and guide the blind and correct the foolish and teach the immature, but do not teach ourselves. Beware lest the Word become a formal thing. An external thing.
If it does not break us, if it does not humble us, if it does not lead us to a sweet, childlike trust in free grace – in other words, if it does not lead us to the Gospel of justification by grace, through faith in Christ – then we are not yet taught by the Word of God, and are not fit to teach others. Woe to me and other teachers and preachers – lovers of the Book – who have in the Word of God the embodiment of knowledge and truth, but only know the letter of the Law and not the Spirit – who only know the form of righteousness and not the righteousness that comes by faith.
Be lovers of the Book, but be also lovers of the God of the Book.