CHASSIDIC PEARLS BY RABBI LAZER BRODY PARSHAS EMOR

The Code of Jewish Law says specifically (Shulchan Oruch, Orach Chaim 98:4) that prayer is a substitute for ritual sacrifices in absence of the holy tabernacle. Therefore, the same criteria required for the sacrifices are also required for prayer.

Rebbe Nachman of Breslev (Likutei Moharan I:14h) cites the Zohar (Yitro, 79) that stipulates, "In a place where one finds the fear of Hashem, one finds perfection." Inversely, a place with no fear of Hashem is blemished. Rebbe Nachman therefore concludes that unblemished prayer requires the fear of Hashem, just as an unblemished sacrifice requires the fear of Hashem.