if ye have - as is the case (this is implied in the Greek indicative).
bitter - Eph 4:31, “bitterness.”
envying - rather, “emulation,” or literally, “zeal”: kindly, generous emulation, or zeal, is not condemned, but that which is “bitter” [Bengel].
strife - rather, “rivalry.”
in your hearts - from which flow your words and deeds, as from a fountain.
glory not, and lie not against the truth - To boast of your wisdom is virtually a lying against the truth (the gospel), while your lives belie your glorying. Jam 3:15; Jam 1:18, “The word of truth.” Rom 2:17, Rom 2:23, speaks similarly of the same contentious Jewish Christians.