There are far more prophets then Isiah, such as Daniel for instance... But when you get a religion producing correct prophecies where the prophets are saying they are from God, and they are sayingtheir purpose is to show God's glory and to 'warn' the future generations...
Seems like you need to explain the prophecies... So explain the prophecies depicted in the bible/Torah?
Idk but maybe the person telling the future correct knows why he is telling the future... If you were solving a math problem such as 2+2 correct you would be able to explain why...![]()
I don't have an explanation for the prophecies, but the explanation that God spoke to someone needs first external evidence that the God in question exists, then that it communicates with us.
Also i have given you the assumption that all the prophecies are 100% accurate, but that also would need external supporting evidence.