It might be helpful to state that God's mercy helps people. Alternate translation: "because God is compassionate and merciful to us" (See: [[rc://en/ta/man/translate/figs-explicit]])
Light is often a metaphor for truth. Here, the spiritual truth the Savior will provide is spoken of as if it is a sunrise that lights up the earth. (See: [[rc://en/ta/man/translate/figs-metaphor]])