Personal Piety means someone is only thinking about themselves and obsessing about their own getting into heaven. Jesus did not teach us to think only of ourselves.
Salvation happened once for everyone, with Resurrection. From that point on we were all asked to bring about God’s new kingdom for everyone, not obsess about whether we were worthy.
Focusing on personal salvation or Personal Piety, is a distraction. It keeps us from seeing the problems in the world that Jesus did ask us to care about and help solve.