What is the ruling regarding my daughter, who has been married for 14 years, remaining with an atheist man who denies the existence of God and the Last Day, and who kicks her while she is prostrating, despite her fear of him? And is it obligatory to refer the matter to the Sharia court?

If a man does not believe in Allah nor in the Last Day, nor does he حرم what Allah and His Messenger have حرمed, nor does he embrace the religion of truth, and he is a sane, conscious individual, then he is an apostate by the consensus of the people of knowledge. The marriage between him and his wife becomes null and void, and she must separate from him by any possible means, such as fleeing or luring him to her country to present the matter to the Sharia judge. He has no right to custody of the children due to the danger this poses to their عقيدة and morals. It is feared that the cause of his deviation is residing in lands of disbelief, therefore a Muslim is advised not to reside there except out of necessity.