All, as they say, that glitters is not gold.

The habit does not make the monk. [Lat., Cucullus (or Cuculla) non facit monachum.]

He's dominated in virtually every appearance. He was the best [available] bullpen guy in the industry.

By outward show let's not be cheated; An ass should like an ass be treated.

We understood Her by her sight; her pure and eloquent blood Spoke in her cheeks, and so distinctly wrought That one might almost say her body thought. - Dr. John Donne,

There's an appearance that we have become what we said we would change.