Does one who intentionally and knowingly misses even one prayer until its time expires become an infidel and depart from the fold of Islam? And what is the ruling on associating with such a person?

Prayer holds a great status in Islam, being the second pillar after the two testimonies of faith, and the first deed of a servant to be examined. Whoever preserves it shall succeed, and whoever neglects it shall fail. A severe warning has been issued against those who are negligent in it. Allah Almighty says: "There succeeded them later generations who neglected prayer and pursued desires; so they are going to meet evil." (19:59) And He says: "So woe to those who pray, [but] who are heedless of their prayer." (107:4-5) Scholars have differed regarding the disbelief of one who intentionally abandons a single prayer until its time expires.