John 8:32-34 And ye shall know the truth, and the truth shall make you free.
8:33 They answered him, We be Abraham's seed, and were never in bondage to any man: how sayest thou, Ye shall be made free?
8:34 Jesus answered them, Verily, verily, I say unto you, Whosoever commits sin is the slave of sin.

We notice a double misunderstanding in these verses.
1. What does Jesus mean by the word "free"?

The Jewish leaders seem to think its a physical meaning of freedom from slavery as practiced in their society.
But Jesus is speaking of spiritual slavery -- slavery to sin. He's referring to freedom from sin.

As Paul understood it: Romans 6:16 Do you not know, that to whom you yield yourselves servants to obey, his servants you are, whom you obey; whether of sin unto death, or of obedience unto righteousness?
In Prov. 5:22The iniquities of the wicked ensnare him, and he is held fast in the cords of his sin
Jesus is speaking of their great need to allow the Holy Spirit to clean out sin in their lives.

Under the influence of the Spirit of God, people are not forced, each person is left free to choose whom they will serve. In the change that takes place in their lives when they surrender to Christ, there is the highest sense of freedom. It's true, we have no power to free ourselves from Satan's control; but when we come to Jesus with the desire to be set free from sin, recognizing our need; God gives us power out of and above ourselves, in fulfilling the will of God.

2. The second misunderstanding concerns being "the seed of Abraham".

The Jews seemed to believe that it's just genetic connection, biological inclusion. Yet Jesus is saying those enslaved to sin are no better off than the Gentiles, even though their lineage connects them to Abraham. True "children" are measured by their similar character and relationship to their Father.
As Paul points out:
Gal. 3:26-29 For we are all the children of God by faith in Christ Jesus.
For as many of you as have been baptized into Christ have put on Christ.
There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
And if you are Christ's, then are you Abraham's seed, and heirs according to the promise.