Uncertainty over historical assertions made within the prayers. An individual may feel that, in the face of uncertainty over the truth of these past or future events, they would rather not testify to their veracity. Theological problems with prayer's form. Jewish liturgy relies heavily on the assumption that there is a single, numinous, external, powerful, loving, compassionate, attentive, merciful, judgemental deity to whom our attention is directed. If an individual is unsure, agnostic or even atheist about the existence of such a god, they may quite legitimately have little incentive to participate.
Jewish prayer can be long, drawn out, slow, tiring, repetitive and hard to understand.
By building communal life around it, we may be erecting a large barrier between a vast number of Jews and meaningful Jewish existence. In short, for a Jew without strong beliefs or habits, it is difficult to find a good reason why they should even try praying, let along take it up regularly. The siddur earned from a barmitzvah or batmitzvah sits on the shelf, collecting dust, and its owner feels that the lack of excitement provided by its contents is a symptom of their heritage's general emptiness. However, it does not take much imagination to come up with a solution which can be practically applied at both the individual and communal level. The activities of prayer and study are closely intermingled and one often sees a student, having finished a particular prayer early, picking up a Talmud for a quick glance before joining in again once the others have caught up.