Anyone who doubts that God will help him is said to be like the water in the ocean or in a large lake, which keeps moving in different directions. (See: [[rc://en/ta/man/translate/figs-simile]])
The word "double-minded" refers to a person's thoughts when he is unable to make a decision. AT: "cannot decide if he will follow Jesus or not" (See: [[rc://en/ta/man/translate/figs-metaphor]])