(edited from Thomas Reade's, "On Unbelief")

It is also a melancholy truth, that unbelief is not
wholly eradicated from the hearts of believers.

Those who are in the habit of observing the secret
movement of their own spirit, will soon perceive how
this subtle evil lies at the bottom of all their languor
in devotion; their inertness of duty; their dulness in
spiritual perception, and their declensions from the
ways of God.

This acquaintance with our own heart will lead us to
the continued exercise of watchfulness and prayer,
through the gracious influence of the Holy Spirit.

A consciousness of inbred sin will cause us to
distrust ourselves, to look continually unto Jesus,
and have no confidence in the flesh.

This salutary fear, implanted in the heart through the
covenant love of God, alone can keep us from falling.

We shall walk over the slippery paths of this sinful
world with safety, when we tread with cautious step,
"leaning upon our beloved."

This knowledge of our inbred sin, when taught by
the Spirit of truth, in connection with the remedy
provided to remove it, even the atoning blood of
Jesus, causes the soul who receives it....
  to sink deep in self abasement;
  to rise high in heavenly affections;
  to renounce the vanities of the world; and
  to grow in a daily fitness for the inheritance of the saints in light.

"Blessed Savior! you who came down from the throne
of glory to die for poor perishing sinners, save me from
the deadly sin of unbelief. Enable me to rely upon you
with the simplicity of a little child. On you may I repose
my soul, for you did bear my sins in your own body on
the tree. Lord save me from self righteousness; from
the love of the world; from pride of heart; from fleshly
indulgence. Keep me near to yourself. Wash me daily
in your cleansing blood from every contracted defilement.
Clothe me with the robe of righteousness, with the
garment of salvation. Cause me to rejoice in you; to
live in the light of your countenance; to taste that you
are gracious; and to glorify you by a growing conformity
to your mind and will."