Will someone who is negligent in their prayers, such as by omitting some of the obligatory prayers or going three days without praying and not attending the mosque, abide eternally in Hell if they die in that state?

The majority of scholars agree that whoever deliberately abandons prayer without excuse until its time has expired is considered a disbeliever. They base this on what has been authentically reported from the Prophet, peace be upon him, and this view was adopted by the Companions and those who followed them. Scholars differed regarding one who prays on some days and abandons it on others. Some went to the extent of saying that one does not disbelieve except by absolute abandonment, while others went to the extent of saying that one disbelieves by abandoning a single prayer. What confirms this is that this ruling was transmitted from seventeen Companions, and they are the most knowledgeable people concerning Allah's religion.