A.B. Simpson emphasizes the importance of trusting God not only for spiritual salvation but also for physical healing and daily needs. He argues that true faith must be practical and applicable to our present circumstances, allowing us to experience God's divine power in our lives. Simpson challenges believers to recognize God as the ultimate source of healing and provision, urging them to transform their trials into blessings through faith. He highlights the significance of understanding Jehovah-rophi, the Lord who heals, and encourages a deeper reliance on God in all aspects of life.

It is very reasonable that God should expect us to trust Him for our bodies as well as our souls. If our faith is not practical enough to bring us temporal relief, how can we be schooled to depend upon God for anything that involves serious risk? It is all very well to talk about trusting God for the distant and future prospect of salvation after death. There is scarcely a sinner in a Christian land who does not trust to be saved some day, but there is no grasp in faith like this. It is only when we come face to face with positive issues and overwhelming forces that we can prove the reality of divine power in a supernatural life. As an education to our spirits as well as a gracious provision for our temporal bodies, God has always trained His people to recognize Him as the supply of all their needs, and to look to Him as the Physician of their bodies and the Father of their spirits. Have we learned the meaning of Jehovah-rophi? (see Exodus 15:23-27). Has it changed our Marah of trial into an Elim of blessing and praise?