The first half of verse 1 has a nice rhythm in Hebrew (which matches the second half):
יי אורי וישעי
Adonai ori v’yishi
Adonai is my light and my rescue;
Of whom shall I be afraid?
יי מעוז חיי
Adonai ma’oz chaiyai
Adonai is the strength of my life
Of whom shall I be in dread?
Who shall I fear? The question is ironic, because the answer is God. While in general it seems that being afraid is a bad thing, the one fear that is positive is fear of God. It is also ironic because, though he is my light (we said this means his face shines with favor on me) and my rescue (even though adversity happens, we said at bottom, God’s plan is rescue), still he is the one I fear, and the only one I need ultimately to fear.
In freeing me of all other fears, I have one fear left. It is God.