The following methods may be employed in order to recognize true prophets and to certify their claims:
1. Miracle: Asking for a miracle is the best and the most satisfactory way to recognize the prophet. If the claimant of prophethood is in possession of miracle or miracles to prove the veracity of his claim, its existence is absolute proof like witnessing or a reliable and definite report and hence his prophethood is proved.
2. Information given by Past Prophets: In case the previous prophet, whose prophethood had been proved, gives information about the advent of the prophet after himself and mentions his distinctive qualities perfectly, the prophethood of the latter would also be proved as happened in case of the Prophet of Islam. The past prophets gave glad tidings of his arrival, which were recorded in their books. Quran has mentioned this same point in the words of Prophet Isa (a.s.):
وَإِذْ قَالَ عِيسَى ابْنُ مَرْيَمَ يَابَنِى إِسْرَآءِيلَ إِنِّى رَسُولُ اللَّهِ إِلَيْكُم مُّصَدِّقاً لِّمَا بَيْنَ يَدَىَّ مِنَ التَّوْرَاةِ وَمُبَشِّراً بِرَسُولٍ يَأْتِى مِن بَعْدِى اسْمُهُ أَحْمَدُ
“And when Isa son of Maryam said: O children of Israel! surely I am the apostle of Allah to you, verifying that which is before me of the Taurat and giving the good news of an Apostle who will come after me, his name being Ahmad…” (61:6)
3. Study of the text of the laws and programs of religion of the prophet: If an intellectual or researcher studies in detail religious cognitions, laws, rules and programs of religion and its different dimensions without prejudice and evaluates them, he can discover the value and comprehensiveness of that religion.
Whether the view of the laws of that religion are according to the criterion of reason and its rules have really complied with the actual needs of the society and that it defends individual rights and social units of the community and observes social justice; and assures the success of man in the world and the hereafter. And by observing its good ethics, which advise its followers to keep away from bad manners etc. he discovers the truthfulness and perfection of that religion and in this way it supports and verifies the prophethood of the prophet.
At this point it is necessary to mention two points: Firstly: Such minute research and indeed all aspects of reformation of people would be limited and cannot become the responsibility of the people. Secondly: In case of certainty, it can be relied upon only within limit of contexts and testimonies, but it cannot be presented as decisive proof. In any case, it does not make us needless of the proof of miracle.
4. Study of life, character and behavior of the claimant of prophethood: If the claimant of prophethood is a person whose trustworthiness, honesty and truthfulness is proved to others and there is no weak point in his internal and external character and he practices what he preaches, he would be supported and verified by the people with regard to the claim of prophethood also. But this topic also would be considered only as a confirmation and not an absolute proof and lawful argument.