A:
Confining the Kufr that takes a person out of Islam to denial only is incorrect. If a Muslim denies a discretionary ruling based on Ijtihad (juristic effort to infer expert legal rulings) concerning which the jurists have differed, it is not considered Kufr. Rather, the person who does so is excused because of continued controversy over it. Those who deliberately abandon some of the Pillars of Islam while they are able to perform them may be judged as disbelievers, like abstaining from pronouncing the Two Testimonies of Faith, in spite of capability, and also abandoning the Five Obligatory Daily Prayers on purpose out of negligence, not out of denial of their obligation.