When one is in a covenant relationship with God through faith in Jesus Christ he comes under the direct care and supervision of the Creator of the universe. Because of Christ he knows that the same Almighty God that created him is the same God (in Christ) that saves him and gives eternal life; and the same God that saves him is the same God that protects and guards Him day and night and forever.
From what God are you needing help? I am getting help from my Creator, my Savior, and my Keeper. The Lord is my Shepherd! I shall not want nor fear. This Keeper is in my presence day and night for physical (sunstroke) and mental (moonstruck) protection and shade. He does not sleep or rest, so I may both sleep in peace and relax in carefree comfort: “He will preserve your soul.”
“All” is an important word for faith to take hold of for peace and comfort: “The Lord will keep you from all evil.” This preservation includes daily comings and goings and longer journeys from now until forever. My unbelief will dispute this promise, but walking by faith wasn’t guaranteed to be easy.