backsliding

Slipping back; falling back into sin or error; sinning.

Turn, O backsliding children, saith the Lord.

Back·slid·ing
n.

The act of one who backslides; abandonment of faith or duty.

Our backslidings are many.

noun

A slipping from a higher or better condition to a lower or poorer one: backslide, lapse, recidivation, recidivism, relapse. See better/worse, repetition.

The noun has one meaning:

Meaning #1: a failure to maintain a higher state
  Synonyms: lapse, lapsing, relapse, relapsing, reversion, reverting