The Valley of Vision book of Puritan Prayers is a goldmine. I pick it up from time to time. I read (and prayed) this one this morning and found a section that is worth sharing.
“Grant that I may never trust my heart,
depend upon any past experiences,
magnify any present resolutions,
but be strong in the grace of Jesus:
that I may know how to obtain relief
from a guilty conscience
without feeling reconciled to my imperfections.”
You can read the whole prayer here at the Banner of Truth website.