6. Which is come unto you--Greek, "Which is present among you," that is, which has come to, and remains with, you. He speaks of the word as a living person present among them.
      as it is in all the world--virtually, as it was by this time preached in the leading parts of the then known world; potentially, as Christ's command was that the Gospel should be preached to all nations, and not be limited, as the law was, to the Jews (Mt 13:38; 24:14; 28:19). However, the true reading, and that of the oldest manuscripts, is that which omits the following "and," thus (the "it is" of English Version is not in the original Greek): "As in all the world it is bringing forth fruit and growing (so the oldest manuscripts read; English Version omits 'and growing,' without good authority), even as it doth in you also." Then what is asserted is not that the Gospel has been preached in all the world, but that it is bearing fruits of righteousness, and (like a tree growing at the same time that it is bearing fruit) growing in numbers of its converts in, or throughout, all the world.
      heard of it--rather, "heard it."
      and knew--rather, "came to know"; became fully experimentally acquainted with.
      the grace of God in truth--that is, in its truth, and with true knowledge [ALFORD].

JFB.