A vulture, a worm eternally gnawing him!

(Thomas Brooks, "Heaven on Earth" 1667)

"And we, who with unveiled faces all reflect the Lord's
 glory, are being transformed into His likeness with
 ever-increasing glory." 2 Corinthians 3:18

Saving knowledge is a transforming knowledge, which
metamorphoses the soul. Divine light beating on the heart,
warms it, and betters it; it transforms and changes it, it
moulds and fashions it into the very likeness of Christ!

The naturalists observe that the pearl, by the often
beating of the sunbeams upon it, becomes radiant.
Just so, the often beating and shining of the Sun of
righteousness, with His divine beams, upon the saints,
causes them to glisten and shine in . . .
  holiness,
  righteousness,
  heavenly-mindedness,
  humbleness, etc.
Divine light casts a general beauty and glory upon
the soul; it transforms a man more and more into
the glorious image of Christ!

Look! as the child receives his features from his parents;
just so, the beams of divine light and knowledge shining
into the soul, stamp the living image of Christ upon the soul.

Mere notional knowledge may make a man excellent at
praising the glorious and worthy acts and virtues of Christ;
but that transforming knowledge which accompanies
salvation, will work a man divinely to imitate the glorious
acts and virtues of Christ.

When a beam of divine light shined from heaven upon Paul, ah,
how did it change and metamorphose him! How did it alter and
transform him! It made his rebellious soul, obedient: "Lord, what
will You have me to do?" Acts 9:6. Divine light lays upon a man
a happy necessity of obeying God. Divine light makes . . .
  this lion--into a lamb,
  this persecutor--into a preacher,
  this destroyer of the saints--into a strengthener of the saints,
  this tormenter--into a comforter,
  this monster--into an angel,
  this notorious blasphemer--into a very great admirer of God,
and the actings of His free grace.

Just so, when a spark of this heavenly fire fell upon the heart of
Mary Magdalene, oh what a change, what a transformation does
it make in her! Now she loves much, and believes much, and
repents much, and weeps much. Oh what a change did divine
light make in Zacchaeus, and in the jailor!

Truly, if your light, your Biblical knowledge does not better you,
if it does not change and transform you; if, under all your light
and knowledge you remain as vile and base as ever; your light,
your knowledge, your notions, your speculations, will undo you.
That knowledge which is not a transforming knowledge--will
torment a man at last more than all the devils in hell; it will be . . .
  a sword to cut him,
  a rod to lash him,
  a serpent to bite him,
  a scorpion to sting him, and
  a vulture, a worm eternally gnawing him!

God at last will own no knowledge, but that which leaves
the stamp of Christ, the print of Christ, the image of Christ
upon the heart; but that which changes and transforms the
soul, which makes a man a new man, another man than
what he was before divine light shined upon him.