NET
3 revealing that you are a letter of Christ, delivered by us, written not with ink but by the Spirit of the living God, not on stone tablets but on tablets of human hearts.
Darby
3 being manifested to be Christ's epistle ministered by us, written, not with ink, but [the] Spirit of [the] living God; not on stone tables, but on fleshy tables of [the] heart.
KJV
3 [Forasmuch as ye are] manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart.