After Bar Mitzva
After a boy becomes bar mitzva and starts putting on tefillin, he feels a surge of excitement of kedusha. If he maintains this enthusiasm for Torah and mitzvos, he can attain the loftiest heights of scholarship and piety. But as he grows older, his fervor cools off, and the youthful exhilaration of his adolescence gradually fades away. As a grown man, he has to work hard to keep a small trace of the fire of devotion to Hashem alive.
Knowing man's weakness, Hashem mercifully sends great tzaddikim down to this world, men with sublime souls who are inspired with a burning love of Hashem and the Jewish people. Klal Yisroel was given the mitzva to cling to the Torah sages and tzaddikim. When a person travels to the tzaddik of his time, establishing a spiritual bond with him, he is uplifted by the tzaddik's holiness and idealism. The ecstasy of his visit with the tzaddik invigorates him and strengthens his emuna, helping him to maintain a high level of devotion that lasts until his next visit.