Prayer in the Teachings of R' Soleveitchik (part 2), Rav Aharon Lichtenstein (summarized by Aviad Hacohen) [VBM, May 1996)
Would we dare act in this way before a king of flesh and blood? Would we shout, demand, request and plead? Where do we find such audacity? How do we allow ourselves such "chutzpa" in our relationship with God?
This led the Rav to speak at length of the necessity for the existence of "permission" (a "mattir") for tefilla, something that would serve as a license of sorts, and in this regard he pointed towards a number of halakhot. For instance, it is stipulated that tefillat nedava, a "voluntary prayer" (i.e., not one of the mandatory, regular communal prayers), must include something innovative. It is not sufficient to simply repeat the tefilla which one has already recited, for this novelty serves as his "permission" to add a non-mandatory prayer...
... The forefathers prayed; so did Moshe Rabbeinu and King David. It would seem, therefore, that even if it seems somewhat paradoxical and even if it contradicts the conclusion we would reach were we to focus on the fundamental, theological, ideological-philosophical aspects alone - it is indeed acceptable, and even desirable.
We are in fact commanded to pray...This indicates both the obligation to pray and the permission to do so. Were it not for the obligation, there would be no permission.
Here the question is directed not towards the issue of permission to pray...so much as towards man's very ability to pray: Is it existentially possible for a person to stand in God's presence?
“Prayer is a vital need for the religious individual. He cannot stop the thoughts and emotions, deliberations and troubles which surge through the depths of his soul, his hopes and aspirations, his despair and bitterness...Prayer is essential. In other words, prayer is justified by virtue of the fact that it is impossible to exist without it.”