That the communication of thy faith may become effectual by the acknowledging of every good thing which is in you in Christ Jesus. That the communication of thy faith - The words ἡ κοινωνια της πιστεως σου, the fellowship or communication of thy faith, may be understood as referring to the work of love towards the saints - the poor Christians, which his faith in Christ enabled him to perform, faith being taken here for its effects; and indeed the word κοινωνια itself is not unfrequently used to denote liberality, almsgiving; and this is very properly remarked by Theophylact here: Κοινωνιαν πιστεως ελεημοσυνην καλει, ὡς απο πιστεως πολλης γενομενην· He terms almsgiving the communication of faith, because it is the fruit of much faith."
May become effectual - Dr. Macknight understands these words thus: "That the many good offices which thou dost to the saints may become effectual in bringing others to the acknowledgment of every good disposition which is in you towards Christ Jesus, or towards his members."
Instead of ενεργης, energetic or effectual, the Vulgate and some of the fathers, as well as several Latin MSS., have read εναργης, evident. This makes a very good sense, and seems to agree best with the scope of the place.
Instead of εν ὑμιν, in You, εν ἡμιν in Us, is the reading of all the best MSS., as well as of several versions and fathers.