A ship may be tossed on the seas, buffeted by storms of every sort. Its crew may be struggling mightily every day simply to keep it afloat, wearying themselves, becoming chilled to the bone. They may fear for their lives every day, and regret ever having set sail with the hopes of adventure and fame and wealth. There may be days when the supplies are running low when they fear starvation. Perhaps every now and again there may be a sunny day, with calm seas, when all is well in the world. The crew may find a moment of rest, such that they might gain some strength to again face the rigors of the voyage.
Prayer is like checking the compass every day to ensure that the ship reaches its destination. It is the hope that comes from this knowledge which sustains the crew, so that they understand that none of the trials of their voyage are in vain.