Create in me a pure heart, O God,
and renew a steadfast spirit within me.
 Do not cast me from your presence
or take your Holy Spirit from me.
 Restore to me the joy of your salvation
and grant me a willing spirit, to sustain me.

Then I will teach transgressors your ways,
so that sinners will turn back to you.

from the penitential Psalm 51:10-13