Our secret sins. — Or, to keep the singular of the original, our secret (character).
The expression, “light of God’s countenance,” usually means “favour.” But here the word rendered light is not the usual one employed in that expression, but rather means a body of light: “the sun (or eye) of Thy countenance.” Comp.:
“Then Seeva opened on the accursed one
His eye of anger.”
SOUTHEY: Curse of Kehama,