A.T. Robertson Commentary 2 Corinthians 6:9

"as unknown, and [yet] well known; as dying, and behold, we live; as chastened, and not killed;" — 2 Corinthians 6:9 (ASV)

As unknown and yet well known (ως αγνοουμενο κα επιγινοσκομενο). "As ignored (as nonentities, obscure, without proper credentials 3:2) and yet fully recognized (by all who really matter as in 11:6)."

And behold, we live (κα ιδου ζωμεν). Cf. the hazards of his life (1:8; 4:10; 11:23). His whole career is full of paradox).