Today's beautiful reading from Isaiah's first chapter talks about God's mercy. No matter how bad our sins are, God can forgive them all and he does forgive them. All we have to do is repent.
In the Gospel Jesus reminds us to be humble: "Whoever humbles himself will be exalted." Humility is honesty, seeing our true position before God. It doesn't mean that we should demean ourselves, but see our true position in God's eyes. But God only looks at us with love, and he sees deep inside us, into our true selves.