2 Corinthians 10:2-4

yea, I beseech you, that I may not when present show courage with the confidence wherewith I count to be bold against some, who count of us as if we walked according to the flesh. For though we walk in the flesh, we do not war according to the flesh (for the weapons of our warfare are not of the flesh, but mighty before God to the casting down of strongholds)