From what we know of Hebrew poetry, we learn to read the lines of the first verse of today's responsorial Psalm as parallel to each other, one complementing the other. We must read "The Lord is my light and my salvation" together with "The Lord is my life's refuge", in order to understand everything that the Psalmist is saying. It is precisely as light and salvation that the Lord is our life's refuge.
"Life's refuge" - we flee to the Lord from all that threatens us because it is in the Lord and with the Lord that we find the fullness of life. Among other descriptions, everything that threatens us can be summed up as darkness and damnation, the polar opposites of light and salvation. If we live lives that move us away from God's light, we are in danger of totally undoing God's work in creating us: we are in danger of falling back into nothingness and chaos, faced with an existence without salvation.
In order to allow us to escape from any threatening darkness and damnation, God sent his Son so that we who sat in darkness and in the shadow of death might in the Risen Jesus see and enjoy the light of salvation.
Lord, grant that I may live in Your house all the days of my life.