The meaning of Belial and its relationship to 2 Corinthains 6:14-7:1

In attempting to reconstruct 2 Corinthians in Marcionite form I came across the problems of the fragmented text, specifically verse 6:14 where the phrase τίς κοινωνία φωτὶ πρὸς σκότος is quoted without regard to placement in Dialogue Adamatius 2.20 and clearly alluded to in Adversus Marcionem 3.8.3. The problem concerns the phrases surrounding, especially the reference to Belial.

James Tabor devotes a page on his website to the Corinthians Correspondence [1] which emphasizes the concept of 2 Corinthians being composed from four distinct documents/letters and a free floating fragment. While I have disagreement with some the specifics, I do find agreement in the labeling of the segment from 6:14-7:1 as "floating" in the Catholic version handed down to us, as clearly 6:11-13 should be joined with 7:2-4. But the Tertullian and Dialogue Adamantius clearly show that at least portions of verses 6:14 and 7:1 were in Marcion's version of 2 Corinthians, while there is no attestation of the text surrounding this "floating" fragment.