Question: since evolution, human development, ways of mental capacity and lifestyles are unlimited in time to come, does it make any reasonable sense to "close" the line of potential profets 1500 years ago, only 5 centuries after the previous one, when humanity MAY live for additional millennia(??) before the final judgement?)
Answer:
1) Prophet & Messenger Muhammad was foretold by the previous scriptures, and his arrival was expected by those who believed in the scriptures:
O People of the Scripture, there has come to you Our Messenger to make clear to you [the religion] after a period [of suspension] of messengers, lest you say, "There came not to us any bringer of good tidings or a warner." But there has come to you a bringer of good tidings and a warner. And Allah is over all things competent.
2) It is an assumption that humanity has a long time to go before the final judgement. Quran Chapter 21 reads:
1 [The time of] their account has approached for the people, while they are in heedlessness turning away.
2 No mention comes to them anew from their Lord except that they listen to it while they are at play
3 With their hearts distracted. And those who do wrong conceal their private conversation, [saying], "Is this [Prophet] except a human being like you? So would you approach magic while you are aware [of it]?"
4 The Prophet said, "My Lord knows whatever is said throughout the heaven and earth, and He is the Hearing, the Knowing."
5 But they say, "[The revelation is but] a mixture of false dreams; rather, he has invented it; rather, he is a poet. So let him bring us a sign just as the previous [messengers] were sent [with miracles]."
6 Not a [single] city which We destroyed believed before them, so will they believe?
7 And We sent not before you, [O Muhammad], except men to whom We revealed [the message], so ask the people of the message if you do not know.
8 And We did not make the prophets forms not eating food, nor were they immortal [on earth].
9 Then We fulfilled for them the promise, and We saved them and whom We willed and destroyed the transgressors.
10 We have certainly sent down to you a Book in which is your mention. Then will you not reason?
11 And how many a city which was unjust have We shattered and produced after it another people.
12 And when its inhabitants perceived Our punishment, at once they fled from it.
13 [Some angels said], "Do not flee but return to where you were given luxury and to your homes - perhaps you will be questioned."
14 They said, "O woe to us! Indeed, we were wrongdoers."
15 And that declaration of theirs did not cease until We made them [as] a harvest [mowed down], extinguished [like a fire].
16 And We did not create the heaven and earth and that between them in play.
17 Had We intended to take a diversion, We could have taken it from [what is] with Us - if [indeed] We were to do so.
18 Rather, We dash the truth upon falsehood, and it destroys it, and thereupon it departs. And for you is destruction from that which you describe.
19 To Him belongs whoever is in the heavens and the earth. And those near Him are not prevented by arrogance from His worship, nor do they tire.
20 They exalt [Him] night and day [and] do not slacken.
21 Or have men taken for themselves gods from the earth who resurrect [the dead]?
22 Had there been within the heavens and earth gods besides Allah, they both would have been ruined. So exalted is Allah, Lord of the Throne, above what they describe.
23 He is not questioned about what He does, but they will be questioned.
24 Or have they taken gods besides Him? Say, [O Muhammad], "Produce your proof. This [Qur'an] is the message for those with me and the message of those before me." But most of them do not know the truth, so they are turning away.
25 And We sent not before you any messenger except that We revealed to him that, "There is no deity except Me, so worship Me."
26 And they say, "The Most Merciful has taken a son." Exalted is He! Rather, they are [but] honored servants.
27 They cannot precede Him in word, and they act by His command.
28 He knows what is [presently] before them and what will be after them, and they cannot intercede except on behalf of one whom He approves. And they, from fear of Him, are apprehensive.
29 And whoever of them should say, "Indeed, I am a god besides Him"- that one We would recompense with Hell. Thus do We recompense the wrongdoers.
30 Have those who disbelieved not considered that the heavens and the earth were a joined entity, and We separated them and made from water every living thing? Then will they not believe?
31 And We placed within the earth firmly set mountains, lest it should shift with them, and We made therein [mountain] passes [as] roads that they might be guided.
32 And We made the sky a protected ceiling, but they, from its signs, are turning away.
33 And it is He who created the night and the day and the sun and the moon; all [heavenly bodies] in an orbit are swimming.
34 And We did not grant to any man before you eternity [on earth]; so if you die - would they be eternal?
35 Every soul will taste death. And We test you with evil and with good as trial; and to Us you will be returned.
36 And when those who disbelieve see you, [O Muhammad], they take you not except in ridicule, [saying], "Is this the one who insults your gods?" And they are, at the mention of the Most Merciful, disbelievers.
37 Man was created of haste. I will show you My signs, so do not impatiently urge Me.
38 And they say, "When is this promise, if you should be truthful?"
39 If those who disbelieved but knew the time when they will not avert the Fire from their faces or from their backs and they will not be aided...
40 Rather, it will come to them unexpectedly and bewilder them, and they will not be able to repel it, nor will they be reprieved.
41 And already were messengers ridiculed before you, but those who mocked them were enveloped by what they used to ridicule.
42 Say, "Who can protect you at night or by day from the Most Merciful?" But they are, from the remembrance of their Lord, turning away.
43 Or do they have gods to defend them other than Us? They are unable [even] to help themselves, nor can they be protected from Us.
44 But, [on the contrary], We have provided good things for these [disbelievers] and their fathers until life was prolonged for them. Then do they not see that We set upon the land, reducing it from its borders? So it is they who will overcome?
45 Say, "I only warn you by revelation." But the deaf do not hear the call when they are warned.
46 And if [as much as] a whiff of the punishment of your Lord should touch them, they would surely say, "O woe to us! Indeed, we have been wrongdoers."
47 And We place the scales of justice for the Day of Resurrection, so no soul will be treated unjustly at all. And if there is [even] the weight of a mustard seed, We will bring it forth. And sufficient are We as accountant.
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109 But if they turn away, then say, "I have announced to [all of] you equally. And I know not whether near or far is that which you are promised.
110 Indeed, He knows what is declared of speech, and He knows what you conceal.
111 And I know not; perhaps it is a trial for you and enjoyment for a time."
112 [The Prophet] has said, "My Lord, judge [between us] in truth. And our Lord is the Most Merciful, the one whose help is sought against that which you describe."
I have not included verses 48-108 above. To read the entire chapter, please go to: http://quran.com/21
