For our boasting is this, the testimony of our conscience, that in simplicity and sincerity before God, a (not in fleshly wisdom but in God's grace,) we have had our conversation in the world, and more abundantly towards you.
Lit. 'simplicity and sincerity of God.' The force I take to be, 'such as God would have, and God would produce.' As we say, 'That is the stroke of a master,' 'the act of a prince.' 'Godly' seems to me feeble, but not wrong. One cannot say 'of God' here.