Spurgeon, "Peter's Restoration" #2034. Luke 22:60-62

Peter's presumption and self-confidence
led to his sad, sad sin. He reckoned that
he could never stumble and for that very
reason he speedily fell. A haughty spirit
goes before a fall. Oh, that we might look
to the roots of bitter flowers and destroy
them! If 'presumption' is flourishing in the
soil of our hearts, we shall soon see the
evil fruit which will come of it.

Reliance upon our firmness of
character, depth of experience,
clearness of insight, or maturity
in grace will, in the end, land
us in disgraceful failure.