What is the ruling on one who hears the Adhan, Iqamah, and prayer but does not come to pray, and what is the ruling on one who only prays the Friday prayer?

He who hears the call and does not answer has no prayer, unless he has a valid excuse, and his prayer is incomplete, and he is sinful for failing to attend the congregational prayer. As for someone who only prays Jumu'ah (Friday) prayer, some scholars believe that he is considered as if he has completely abandoned prayer; because he only prays one prayer out of 35 prayers in a week. While others believe that he does not become an infidel, but he commits a great crime, more severe than usury and fornication.