The Greek of this verse is literally “and they were not able to resist the wisdom and the spirit with which he was speaking.” Most commentators and translators agree that the spirit referred to is the Holy Spirit, and the sentence construction lends itself to the interpretation of the text that the Good News Translation has given: But the Spirit gave Stephen such wisdom that when he spoke they could not resist him (see also Jerusalem Bible, “they found they could not get the better of him because of his wisdom, and because it was the Spirit that prompted what he said”).

Gave … such wisdom is equivalent in some languages to “caused him to be so wise” or “caused him to speak such wise words.”

The expression could not resist him may be rendered as “were not able to answer him” or “were not able to argue against him.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .