There is a well-known saying of our Sages: “You cannot compare a few who perform [the commandments of] the Torah to many who perform [the commandments of] the Torah [together]” (Sifra, Bechukosai), because the more people who do a mitzvah together, the more the mitzvah is elevated. It is thus written, A multitude of people is a king’s glory (Mishlei 14:28). Now, with regard to prayers, it is a very great need to pray with a group, for the prayer of an individual—especially in an orphaned generation such as ours—is virtually repelled. For there are many conditions required for the prayer of an individual to be accepted: that it be said with great focus and that the person be clean of sin, so that one’s prayer will rise and find favor before Hashem. And even then, the person is still not guaranteed that his prayer will be accepted. So who can be so confident, in our times, to pray in private and think that his prayer will be pleasing to Hashem? Therefore, one who desires life will not pray alone, unless it is a situation of absolute necessity, because by doing so he loses much good, such as answering “Amen” and Yehei Shmei Rabbah, Borchu, and Kedushah; also, his prayer will be troubled and barren, unable to produce fruit.