“Fear of punishment freezes people and prevents them from making any real change.”
the above is Bowzers opinion.
R” Yisroel Salanter in Ohr Yisroel stresses over and over that the most important thing that all Yidden must work on and devote time every day to contemplate, is fear of punishment, in this world and primarily in the World To Come.
Msilus Yesharim and Chovos HaLavovos and Shareii Tshuvah also spend a great deal of time discussing the critical nature of fear of punishment.