It is forbidden for fear of Heaven to push aside one’s natural morality, for then it would no longer be pure fear of Heaven. The sign [by which one can recognize] pure fear of Heaven is when the natural morality which is rooted in man’s honest nature ascends by means of [the fear of Heaven] to higher levels than it would have attained without it.
But if there should be a fear of Heaven, such that without its influence, life would tend to function better, and would actualize things beneficial to the individual and society, whereas with its influence that actualizing power would diminish — such a fear of Heaven is invalid.[1]
Founding Chief Rabbi AI KOOK (Orot Hakodesh, Vol. III, p.27., quoted by Rabbi Yehuda Amital zt’l)