The If clause in this verse relates back to verse 34. New English Bible translates the Greek particle introducing this verse “If then” and New American Bible “That is why, if.”

The Jews considered themselves free, but they were not really free; real freedom comes only as the Son makes one free. Die Bibel im heutigen Deutsch translates the Son as the Son of God, making explicit for its readers what Good News Translation and other translations try to achieve by capitalizing the word Son. To do so is translationally legitimate, and it may be an especially helpful device to German readers, since all nouns, without distinction, are capitalized in German. In some languages it is necessary to employ the phrase “God’s Son,” since the kinship term “Son” must be possessed.

The adverb really of this verse (ontōs), though not the same as the one used in verse 31 (alēthōs), is synonymous in meaning.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .