'Vigorous' in the Bible

sound and beyond reproach in instruction, so that the opponent [of the faith] will be shamed, having nothing bad to say about us.

I have written to you, fathers, because you know Him who has existed from the beginning. I have written to you, young men, because you are strong and vigorous, and the word of God remains [always] in you, and you have been victorious over the evil one [by accepting Jesus as Savior].