Criteria to use to check the validity of a Prophet of God

… the proofs of the validity and inspiration of a Prophet of God are the deeds of beneficent accomplishment and greatness emanating from Him. If He proves to be instrumental in the elevation and betterment of mankind, He is undoubtedly a valid and heavenly Messenger. (Abdu'l-Baha, The Promulgation of Universal Peace, p. 366)