David calls out to the Lord to preserve him, to keep him safe in whatever he faces in life. He focuses on the Lord; that He is his refuge and that God alone is the source of all good. David will not look to other gods and will worship the Lord God and keep Him always before him. The Lord is the One who draws the boundary lines of our life and even if sometimes it seems too difficult or not where we want to be, God will support us and bring us through it.
We are to listen when the Lord speaks and counsels us; thus we are to continually be aware of His presence and His guidance and take confidence that His presence is always with us. We have a heritage and inheritance that go beyond this life. Even through difficult times, we can trust the Lord to guide us and give us continual joy in His presence.