1 Corinthians 8:11

“For the weak man [whom you talk of building up!] is being destroyed through thy knowledge the brother, on whose account Christ died!” (Romans 14:15). This affirms, with terrible emphasis, the issue implied by 1 Corinthians 8:10 : “est ædificatio ruinosa” (Cv [1267]). ὁ ἀσθενῶν means (more than ὁ ἀσθενής) the man in a continued state of weakness. ἐν τῇ σῇ γνώσει, “on the ground (or in the sphere) of thy knowledge”; in this atmosphere the weak faith of the other cannot live (cf. ἐν in 1 Corinthians 2:4; Ephesians 4:16, ἐν ἀγάπῃ). His “knowledge” leaves the tempter inexcusable. “Notice the threefold darkness of the picture: there perishes, thy brother, for whom Christ died” (Bt [1268]). Paul appeals to the strongest feelings of a Christian brotherly love and loyalty to Christ. For the prospective διʼ ὅν, cf. Romans 4:25; Christ's death is thus frustrated of its dear object (cf. Galatians 2:21) by thy heartless folly!

[1267] Calvin's In Nov. Testamentum Commentarii.

[1268] J. A. Beet's St. Paul's Epp. to the Corinthians (1882).