but . . . you should be made new in the force actuating your mind,

You may feel that the “force actuating your mind” (literally, ‘the spirit of your mind’) is not strong enough. True, you may not be strong enough in yourself. But by your dedication you have placed yourself in Jehovah’s hand, and he is strong enough. He is both able and willing to guide and strengthen you to do your part. “For God is the one that, for the sake of his good pleasure, is acting within you in order for you both to will and to act.” (Phil. 2:13) You do not need to rely on the force or spirit of your own mind. Rather, you learn how to cooperate with God’s spirit.