And We have set none but angels as guardians of the Fire, and We have fixed their number (19) only as a trial for the disbelievers, in order that the people of the Scripture (Jews and Christians) may arrive at a certainty [that this Quran is the truth as it agrees with their Books i.e. their number (19) is written in the Taurat (Torah) and the Injeel (Gospel)] and the believers may increase in Faith (as this Quran is the truth) and that no doubts may be left for the people of the Scripture and the believers, and that those in whose hearts is a disease (of hypocrisy) and the disbelievers may say: "What Allah intends by this (curious) example?" Thus Allah leads astray whom He wills and guides whom He wills. And none can know the hosts of your Lord but He. And this (Hell) is nothing else than a (warning) reminder to mankind.
Nay, everyone of them desires that he should be given pages spread out (coming from Allah with a writing that Islam is the right religion, and Muhammad SAW has come with the truth from Allah the Lord of the heavens and earth, etc.).
And they will not receive admonition unless Allah wills; He (Allah) is the One, deserving that mankind should be afraid of, and should be dutiful to Him, and should not take any Ilah (God) along with Him, and He is the One Who forgives (sins).
IMPORTANT: All Scripture text has context and background. Scripture should never be read literally or in isolation. Always seek clarification from religious scholars and teachers. In general, Scripture adheres to four principles: (1) Literal Meaning - What the Scripture says (2) Historical Setting - The story events; how the Scripture was understood in its time (3) Grammar - The surrounding sentence and paragraph; textual context (4) Synthesis - A comparison with similar Scripture to give a better contextual understanding