The third sermon in this series emphasizes serving God acceptably through a commitment to righteousness, peace, and edification rather than judgment. It explores the concept of imputed and imparted righteousness, highlighting the importance of meditating on God's word and presenting one's body as a living sacrifice. The message underscores the need to separate from unrighteousness, prioritize spiritual growth, and embrace suffering for Christ's sake, ultimately leading to a life of purpose and blessing for both the individual and those around them.