'Powerful' in the Bible

for the weapons of our warfare [are] not merely human, but powerful to God for the tearing down of fortresses, tearing down arguments

because it is said, "His letters [are] severe and powerful, but his bodily presence [is] weak and his speech is of no account."

since you are demanding proof that Christ, who [is] not weak toward you, but is powerful among you, is speaking in me.