Fragment 8, on John 1:26 (In John 1:26-27, “John answered them, ‘I baptize with water; but there stands among you one whom you do not know, even he who comes after me, the thong of whose sandal I am not worthy to untie.’”) The words, "there stands among you” are equivalent to "He is already here, and he is in the world and among human beings, and he is already manifest to you all.” . . . The statement, "He who comes after me," shows John to be the forerunner of Christ, for he is in fact a kind of servant running before his master. In the words, “The thong of his sandal I am not worthy to untie,” the Baptist acknowledges that he is not worthy even of the lowliest service for Christ. . . (He means,) "I am not worthy that for my sake he should come down from the Greatness and should assume flesh as his sandal, concerning which I am not able to give any explanation or description, nor to unloose the arrangement of it." . . . The sandal means the world. . . Everything must be understood in relation to that person who was indicated through John, that is the Craftsman of the world, who acknowledges through these words that he is inferior to Christ.
Hence the Valentinians were going to judaize, differently from other Gnostics (as Marcion).