An insatiable thirst after larger attainments

(John Angell James, "Small Beginnings Not to Be Despised")

The man who thinks he has enough godliness--gives a
decisive proof that he has none at all. There is in true
piety, an insatiable thirst after larger attainments . . .
  in knowledge,
  in faith,
  in hope,
  in love,
  in purity.

Therefore let every real Christian adopt the language of
Paul, and act up to the assertion, "Not that I have already
reached the goal or am already fully mature, but I make
every effort to take hold of it because I also have been
taken hold of by Christ Jesus. Brothers, I do not consider
myself to have taken hold of it. But one thing I do--
forgetting what is behind and reaching forward to what
is ahead, I pursue as my goal the prize promised by
God's heavenly call in Christ Jesus." Philippians 3:12-14