A.T. Robertson Commentary 2 Corinthians 1:12

"For our glorifying is this, the testimony of our conscience, that in holiness and sincerity of God, not in fleshly wisdom but in the grace of God, we behaved ourselves in the world, and more abundantly to you-ward." — 2 Corinthians 1:12 (ASV)

Glorying (καυχησις). Act of glorying, while in verse 14 καυχημα is the thing boasted of.

The testimony of our conscience (το μαρτυριον της συνειδησεως ημων). In apposition with καυχησις.

Sincerity of God (ειλικρινεια του θεου). Like δικαιοσυνη θεου (Romans 1:17; Romans 3:21), the Godkind of righteousness. So the God-kind (genitive case) of sincerity. Late word from ειλικρινης. See on 1 Corinthians 5:8.

Not in fleshly wisdom (ουκ εν σοφια σαρκικη). See on 1 Corinthians 1:17; 2:4,13f. Paul uses σαρκικος five times and it occurs only twice elsewhere in N.T. See on 1 Corinthians 3:3.

We behaved ourselves (ανεστραφημεν). Second aorist passive indicative of αναστρεφω, old verb, to turn back, to turn back and forth, to walk. Here the passive is used as in late Greek as if middle.

More abundantly to you-ward (περισσοτερως προς υμας). They had more abundant opportunity to observe how scrupulous Paul was (Acts 18:11).