From: John 8:31-42
Jesus Warns the Unbelieving Jews (Continuation)
 Jesus then said to the Jews who had believed in Him, "If you continue in My word, you are truly My disciples,  and you will know the truth, and the truth will make you free."  They answered Him, "We are descendants of Abraham, and have never been in bondage to any one. How is it that you say, `You will be made free'?"
 Jesus answered them, "Truly, truly, I say to you, every one who commits sin is a slave of sin.  The slave does not continue in the house for ever; the son continues for ever.  So if the Son makes you free, you will be free indeed.  I know that you are descendants of Abraham; yet you seek to kill Me, because My word finds no place in you.  I speak of what I have seen with My Father, and you do what you have heard from your father."
 They answered Him, "Abraham is our father." Jesus said to them, "If you were Abraham's children, you would do what Abraham did,  but now you seek to kill Me, a man who has told you the truth which I heard from God; this is not what Abraham did.  You do what your father did." They said to Him, "We were not born of fornication; we have one Father, even God."  Jesus said of them, "If God were your Father, you would love Me, for I proceeded and came forth from God; I came not on My own account, but He sent Me."
30-32. Of those Jews who do believe in Him Jesus asks much more than a shallow faith resulting from superficial enthusiasm: they should be true disciples; Jesus' words should imbue their whole life. That kind of faith will bring them to know the truth and to become really free persons.
The knowledge of the truth which Christ is speaking about is not just intellectual knowledge; it is rather the maturing in the soul of the seed of divine Revelation. That Revelation's climax is to be found in Christ's teaching and it constitutes a genuine communication of supernatural life (cf. John 5:24): He who believes in Jesus, and through Him in the Father, receives the wonderful gift of eternal life. Knowing the truth is, in the last analysis, knowing Christ Himself, God become man to save us; it means realizing that the inaccessible God has become man, our Friend, our Life.
This is the only kind of knowledge which really sets us free, because it removes us from a position of alienation from God--the state of sin and therefore of slavery to the devil and to all attachments of our fallen nature--and puts us on the path of friendship with God, the path of grace, of the Kingdom of God. Therefore, the liberation we obtain is not just light which shows us the way; it is grace, which empowers us to keep to that way despite our limitations. "Jesus Christ meets the man of every age, including our own, with the same words: `You will know the truth, and the truth will make you free' (John 8:32). These words contain both a fundamental requirement and a warning: the requirement of an honest relationship with regard to truth as a condition for authentic freedom, and the warning to avoid every kind of illusory freedom, every superficial unilateral freedom, every freedom that fails to enter into the whole truth about man and the world. Today also, even after two thousand years, we see Christ as the One who brings man freedom based on truth, frees man from what curtails, diminishes and as it were breaks off this freedom at its root, in man's soul, his heart and his conscience. What a stupendous confirmation of this has been given and is still being given by those who, thanks to Christ and in Christ, have reached true freedom and have manifested it even in situations of external constraint!" (John Paul II, "Redemptor Hominis", 12).
"Christ Himself links liberation particularly with knowledge of the truth; `You will know the truth and the truth will make you free' (John 8:32). This sentence testifies above all to the intimate significance of the freedom for which Christ liberates us. Liberation means man's inner transformation, which is a consequence of the knowledge of truth. The transformation is, therefore, a spiritual process, in which man matures `in true righteousness and holiness' (Ephesians 4:24). [...] Truth is important not only for the growth of human knowledge, deepening man's interior life in this way; truth has also a prophetic significance and power. It constitutes the content of testimony and it calls for testimony. We find this prophetic power of truth in the teaching of Christ. As a prophet, as a witness to truth, Christ repeatedly opposes non-truth; He does so with great forcefulness and decision and often He does not hesitate to condemn falsehood" (John Paul II, "General Audience", 21 February 1979).
St. Thomas Aquinas explains the meaning of these words of our Lord in this way: "In this passage, being made free does not refer to being freed of every type of wrong [...]; it means being freed in the proper sense of the word, in three ways: first, the truth of His teaching will free us from the error of untruth [...]; second, the truth of grace will liberate us from the slavery of sin: `the law of the Spirit of life in Christ Jesus has set me free from the law of sin and death' (Romans 8:2); third, the truth of eternity in Christ Jesus will free us from decay (cf. Romans 8:21)" ("Commentary on St. John, in loc.").
"The truth will set you free. How great a truth is this, which opens the way to freedom and gives it meaning throughout our lives. I will sum it up for you, with the joy and certainty which flow from knowing there is a close relationship between God and His creatures. It is the knowledge that we have come from the hands of God, that the Blessed Trinity looks upon us with predilection, that we are children of so wonderful a Father. I ask my Lord to help us decide to take this truth to heart, to dwell upon it day by day; only then will we be acting as free men. Do not forget: anyone who does not realize that he is a child of God is unaware of the deepest truth about himself. When he acts he lacks the dominion and self-mastery we find in those who love our Lord above all else" ([St] J. Escriva, "Friends of God", 26).
33-34. For centuries the people of Israel were ruled by other nations (Egypt, Babylon, Persia...), and now they were under the dominion of Rome. Therefore, the Jews thought that He was referring to political bondage or dominion--which in fact they had experienced but never accepted. In addition, since they belong to the people chosen by God, they regarded themselves as free of the moral errors and aberrations of Gentile nations.
They thought that true freedom was a matter of belonging to the chosen people. Our Lord replies that it is not enough to belong to the line of Abraham: true freedom consists in not being slaves of sin. Both Jews and Gentiles were subject to the slavery of original sin and personal sin (cf. Romans 5:12; 6:20 and 8:2). Only Christ, the Son of God, can liberate man from that sorry state (cf. Galatians 4:21-51); but these Jews do not understand the redemptive work which Christ is doing and which will reach its climax in His death and resurrection
"The Savior", St. Augustine comments, "is here explaining that we will not be freed from overlords, but from the devil; not from captivity of the body but from malice of soul" ("Sermon", 48).
35-36. The words slave and son are reminiscent of the two sons of Abraham: Ishmael, born of the slave woman Hagar, who would be given no part in the inheritance; and Isaac, son of the free woman Sarah, who would be the heir to God's promises (cf. Genesis 21:10-12; Galatians 4:28-31). Physical descent from Abraham is not enough for inheriting God's promises and attaining salvation: by faith and charity one must identify oneself with Jesus Christ, the true and only Son of the Father, the only one who can make us sons of God and thereby bring us true freedom (cf. Romans 8:21; Galatians 4:31). Christ gives "power to become children of God [to those] who were born, not of blood nor of the will of the flesh, nor of the will of man, but of God" (John 1:12-13). Thus, a person who identifies himself with Christ becomes a son of God and obtains the freedom proper to sons.
"Freedom finds its true meaning when it is put to the service of the truth which redeems, when it is spent seeking God's infinite Love which liberates us from all forms of slavery. Each passing day increases my yearning to proclaim to the four winds this inexhaustible treasure that belongs to Christianity: `the glorious freedom of the children of God!' (Romans 8:21). [...] Where does our freedom come from? It comes from Christ our Lord. This is the freedom with which He has ransomed us (cf. Galatians 4:31). That is why He teaches, `if the Son makes you free, you will be free indeed' (John 8:36). We Christians do not have to ask anyone to tell us the true meaning of this gift, because the only freedom that can save man is Christian freedom" ([St] J. Escriva, "Friends of God", 27 and 35).
37-41. Our Lord replies to the Jew's objection: yes indeed, they are Abraham's children, but only in a natural sense, according to the flesh; this is something which does not count any more; what matters now is acceptance of Jesus as the One sent by the Father. Jesus' questioners are spiritually very far away from being true children of Abraham: Abraham rejoiced to see the Messiah (cf. John 8:56); through his faith he was reckoned righteous (cf. Romans 4:1ff), and his faith led him to act consequentially (cf. James 2:21-24); this was how he attained the joy of eternal blessedness (cf. Matthew 8:11; Luke 16:24). Although those Jews "derived from him the generation of the flesh, they had become degenerate, by not imitating the faith of him whose sons they were" (St. Augustine, "In Ioann. Evang.", 42, 1). Those who live by faith, St. Paul says, are the true sons of Abraham and like him they will be blessed by God (cf. Galatians 3:7-9). In point of fact, the people who are arguing with our Lord have not only rejected His teaching: their own deeds indicate that they have a radically different affiliation: "You do what your father did" is a veiled accusation that they are children of the devil (cf. verse 44).
The false security Jews felt on the grounds of being descended from Abraham has its parallel in a Christian who is content with being baptized and with a few religious observances, but does not live up to the requirements of faith in Christ.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.