So if the Son sets you free, you will be free indeed.
36. If then the Son shall make you free. By these words he means that the right of freedom belongs to himself alone, and that all others, being born slaves, cannot be delivered but by his grace. For what he possesses as his own by nature he imparts to us by adoption, when we are ingrafted by faith into his body, and become his members.
We have in these verses, I. A comfortable doctrine laid down concerning the spiritual liberty of Christ's disciples, intended for the encouragement of those Jews that believed. Christ, knowing that his doctrine began to work upon some of his hearers, and perceiving that virtue had gone out of him, turned his discourse from the proud Pharisees, and addressed himself to those weak believers.
Commenting on John 8:31-37
They answered and said unto him,.... On account of his making mention of a father, whose works they did, and whom they imitated: Abraham is our father; meaning their only one, nor had they any other: Jesus saith unto them, if ye were Abraham's children, ye would do the works of Abraham; for who should children imitate but their parents?