A chassid once asked the Tzemach Tzedek to bless his son with a good memory so he would remember all that he would see and hear from the Rebbe and chassidim, and therefore be automatically G-d-fearing.

The Rebbe responded: For over fifty years, my grandfather (the Alter Rebbe), my father-in-law (the Mitteler Rebbe) and I have endeavored to teach Jews to "earn" their fear of G-d by their avodah (performance of mitzvos and study of Torah). Do you want me to deprive your son of this great merit - to become a G-d-fearing Jew by dint of his service to the Creator?

Likkutei Sichos, vol. 3, p. 800; Sefer HaSichos 5700, p. 57