Why will God raise (revive) the entire mankind after death on the Day of Judgement (Hereafter)?

Verses 38-40 of Chapter 16:

They solemnly swear by God with their most sacred oaths that "Allah will never raise him who once is dead". Why will He not raise? It is a promise He has made binding on Himself, but most people do not know it. And It must be fulfilled so that He may reveal to them that thing about which they are differing, and that the disbelievers might know that they were liars. (As regards its possibility.) when We desire to bring a thing into existence, We need only say, "Be", and it is there.

Why does God not guide those whom He  leaves to astray?

Verses 35-37 of Chapter 16:

The worshippers of false gods say: "If Allah had so willed, we should not have worshipped aught but Him - neither we nor our fathers,- nor should we have prescribed prohibitions other than His." So did those who went before them. But what is the mission of messengers but to preach the Clear Message? For We assuredly sent amongst every People a messenger, (with the Command), "Serve Allah, and eschew Evil": of the People were some whom Allah guided, and some on whom error became inevitably (established). So travel through the earth, and see what was the end of those who denied (the Truth). If thou art anxious for their guidance, yet Allah guideth not such as He leaves to stray, and there is none to help them.

People who do not believe in the Hereafter or dislike worshipping God do so on account of their pride!

Verses 22-23 of Chapter 16:

Your god is one God. But for those who believe not in the Hereafter, their hearts are in denial, and they are proud.) (23. Certainly, Allah knows what they conceal and what they reveal. Truly, He does not like the proud.

Verse 60 of Chapter 40:

Your Lord says: "Call upon Me. I will answer your prayers. Those who disdain My worship on account of pride, shall certainly enter Hell, disgraced."

On the Day of Judgement, there will be people who will bear not only the full burdens of their sins, but also some burdens of others whom they misled!

Verses 24-25 of Chapter 16:

And when they are asked, "What is it that your Lord has sent down?" they say these are mere fairy tales of the ancients.They say such things so that they should bear the full brunt of their own burdens on the Day of Resurrection together with some of the burdens of those whom they are leading astray in their ignorance. Behold! what a heavy responsibility they are taking on themselves!

Whom does God guide to the right pathway? What is the only way to find comfort in hearts?

Verses 27-29 of Chapter 13:

And those who disbelieved say: "Why is not a sign sent down to him from his Lord'' Say: "Verily, Allah sends astray whom He wills and guides unto Himself those who turn to Him in repentance.'' Those who believed and whose hearts find rest in the remembrance of Allah. Verily, in the remembrance of Allah do hearts find rest. Those who believed, and work righteousness, Tuba is for them and a beautiful place of (final) return.

Does Al-Q'uran possess guidance in sufficient details for human beings?

Verses 111 of Chapter 12:

Indeed in their stories, there is a lesson for men of understanding. It (the Qur'an) is not a forged statement but a confirmation of that which was before it and a detailed explanation of everything and a guide and a mercy for the people who believe.

Verse 89 of Chapter 16:

And on the Day when We resurrect a witness from each nation from among themselves, and We bring you (O Muhammad) as a witness against these. And We have revealed the Book (the Qur'an) to you as an explanation of everything, a guidance, a mercy, and good news for the Muslims.

Verse 89 of Chapter 17:

And indeed We have fully explained to mankind, in this Qur'an, every kind of similitude, but most of mankind refuse (the truth and accept nothing) but disbelief. 

Verse 54 of Chapter 18:

We have devised different ways in the Qur'an to make the people understand its Message, but man is by nature very contentious.