If you instruct the brothers of these things, you will be a good servant of Christ Jesus, nourished in the words of the faith, and of the good doctrine which you have followed.
whereunto thou hast attained: This phrase establishes beyond question that Paul is not censuring Timothy for having failed to study or having failed to do his duty, nor is he indicating that Timothy was a timid fellow fearful of doing his work. Instead, he is encouraging Timothy to continue what he has already been doing, to remain on the course he has been pursuing. He is to keep on nourishing his mind on God’s word as he has done faithfully all along.