“His truth will surround you with a shield” (Ps 90[91]: 5). His truth is like a shield so that it doesn’t confuse those who hope in themselves with those who hope in God. Here’s a sinner, and there’s a sinner. One of them presumes in himself, despises others, doesn’t confess his sins, and says, “If God were displeased with my sins, he wouldn’t allow me to live.” The other sinner didn’t dare raise his eyes, but struck his breast, saying “Lord, be merciful to me a sinner” (Lk 18:13). He’s a sinner; the other one’s a sinner, but one mocks, and the other weeps; one despises, the other confesses his sins. But God’s truth, which does not accept persons, distinguishes the penitent from the defender, distinguishes the lowly one from the proud one, distinguishes the one who presumes on himself from the one who presumes on God. “His truth,” therefore, “will surround you like a shield.” (Augustine, EnPs 80[91]/1, 6; PL 37, 1153)