Verses with the word foolishly in the New Testament (2 verses):

2 Corinthians 11:17
That which I speak, I speak it not after the Lord, but as it were foolishly, in this confidence of boasting.

2 Corinthians 11:21
I speak as concerning reproach, as though we had been weak. Howbeit whereinsoever any is bold, (I speak foolishly,) I am bold also.