"But that is not the way you learned Christ!-- assuming that you have heard about him and were taught in him, as the truth is in Jesus..." (Ephesians 4:20-21 ESV)
What does it mean, "you learned Christ"? Here are some highlights from Martyn Lloyd-Jones' sermon on this passage:
"Christianity is not a vague, indefinite, nebulous kind of feeling or experience; patently it is something which can be defined and described; it is primarily a matter of knowledge."
"The Christian therefore, by definition, is a man whose eyes have been opened, while the unbeliever is still blinded by the god of this world."
"How then has it all happened? There is only one explanation-- this is the work of the Holy Spirit. Nothing else, nobody else, can do this but the Holy Spirit. It is His special, His peculiar work. It is He alone who can remove the veil from the heart."
"This truth is the most glorious thing we can ever realize together. It is not primarily man's natural ability that matters. That must not be discounted, but to become a Christian does not depend upon one's natural ability and understanding. Thank God for that!"
"The learning that is given to believers is not merely a learning about doctrine and theology in a purely intellectual and theoretical manner. Such learning is of no value to us at all, indeed it may be a curse to us."
"A man cannot be a Christian without doctrine; he does not know what he believes otherwise; but you can have it in your mind, you can have it in theory, but as such it will be of no value to you at all; it is outside you, it has not moved you, it has not gripped your life, it has not changed you, it has not made you more and more conformable to the pattern and the example of the Lord Jesus Christ."
"We must not think of salvation in loose, vague terms; we must not talk about some great cosmic Christ who exerts an influence upon men in the world; we must not hold to salvation merely as an idea and as a concept and as a thought. Not at all! The Apostle says we must think it all out in terms of Jesus. Now this Apostle of all men is fond of using the full term the Lord Jesus Christ, but here he says, 'as the truth is in Jesus'. And for this good reason, that the Christian is not saved by a philosophy of redemption; he is saved by the historic Person, Jesus of Nazareth, Son of God!"
"God forbid, I say again, that we should ever separate our doctrine from His Person! God forbid that we should become academic and theoretical and detached, and forget even for a second that salvation has come in a Person, in this particular Person, Jesus, in whom God has stored all the treasures of His own wisdom and His own knowledge."
~ Martyn Lloyd-Jones, "Knowledge of the Truth" in Darkness and Light: An Exposition of Ephesians 4:17--5:17 (Baker Books, 1982)
Hear the original sermon in full here: "The Knowledge of the Truth"