In order to eliminate this problem, Allah (s.w.t.) has given us the decision in this manner: وَرَبُّكَ يَخْلُقُ مَا يَشَاء وَيَخْتَارُ مَا كَانَ لَهُمُ الْخِيَرَةُ سُبْحَانَ اللَّهِ وَتَعَالَى عَمَّا يُشْرِكُونَ [Shakir 28:68] And your Lord creates and chooses whom He pleases; to choose is not theirs; glory be to Allah, and exalted be He above what they associate (with Him). This verse has decisively stated that people have no right to chose or make their own claims.
This right belongs to Allah (s.w.t.) and whoever does this then he would be committing ‘Shirk’ (Polytheism). If someone were to make a claim then we will have to see whether he has got the divine authorisation in order to do so. If he does, then we will bow down our heads and accept his claim even if no one else does, but, if he does not, then we will reject him even if the whole world were to accept him.
If you were to browse through the Holy Quran you will see that whenever Allah (s.w.t.) chose a Prophet, then He (s.a.w.) did not whisper it into his ears, rather he was told to make a general announcement of it. Let us now look at some verses.
وَقَالَتِ الْيَهُودُ لَيْسَتِ النَّصَارَى عَلَىَ شَيْءٍ وَقَالَتِ النَّصَارَى لَيْسَتِ الْيَهُودُ عَلَى شَيْءٍ وَهُمْ يَتْلُونَ الْكِتَابَ كَذَلِكَ قَالَ الَّذِينَ لاَ يَعْلَمُونَ مِثْلَ قَوْلِهِمْ فَاللّهُ يَحْكُمُ بَيْنَهُمْ يَوْمَ الْقِيَامَةِ فِيمَا كَانُواْ فِيهِ يَخْتَلِفُونَ [Shakir 2:113] And the Jews say: The Christians do not follow anything (good) and the Christians say: The Jews do not follow anything (good) while they recite the (same) Book.
Even thus say those who have no knowledge, like to what they say; so Allah shall judge between them on the day of resurrection in what they differ.
لَقَدْ أَرْسَلْنَا رُسُلَنَا بِالْبَيِّنَاتِ وَأَنزَلْنَا مَعَهُمُ الْكِتَابَ وَالْمِيزَانَ لِيَقُومَ النَّاسُ بِالْقِسْطِ وَأَنزَلْنَا الْحَدِيدَ فِيهِ بَأْسٌ شَدِيدٌ وَمَنَافِعُ لِلنَّاسِ وَلِيَعْلَمَ اللَّهُ مَن يَنصُرُهُ وَرُسُلَهُ بِالْغَيْبِ إِنَّ اللَّهَ قَوِيٌّ عَزِيزٌ [Shakir 57:25] Certainly We sent Our messengers with clear arguments, and sent down with them the Book and the balance that men may conduct themselves with equity; and We have made the iron, wherein is great violence and advantages to men, and that Allah may know who helps Him and His messengers in the secret; surely Allah is Strong, Mighty.
This means that whenever Allah (s.w.t.) sent someone then it was accompanied with clear proofs and arguments.