To leave the congregational prayer (Jama'at) without a Shari'ah excuse is a great deprivation, and it is to abandon a major symbol (Sha'air) of Islam. According to the respected jurists (Fuqaha), the testimony (witness) of this person who leaves the congregation will not be accepted and he will be a sinner. Severe warnings have been narrated regarding this in the Hadith Sharif; the Holy Prophet (peace be upon him) said: "The prayer which he offered will not be accepted from him." (Aham Masail / Vol: 1 / Pg: 32)