Andrew Murray emphasizes the necessity of walking by the Spirit to overcome the flesh, contrasting the healthy Christian life with one that merely exists by the Spirit without active obedience. He explains that true believers must not only recognize their new life in Christ but also actively engage in a Spirit-led life, which requires the crucifixion of the flesh and its desires. Murray warns against the dangers of self-reliance and the flesh's subtle influence in religious practices, urging believers to fully surrender to the Holy Spirit for empowerment. He highlights that understanding and accepting the crucifixion of the flesh is essential for living a victorious Christian life. Ultimately, he calls for a deep reliance on the Holy Spirit to maintain a life that is pleasing to God.