All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is mentioned in the Quran that the children of Israel were favored over the worlds during their time because there were among them prophets, callers to Allaah The Almighty and reformers. There was no nation that had the same number of prophets among them like the children of Israel at the time.
Allaah The Almighty reminded them in the Quran of this fact. Allaah The Almighty Says (what means): {O children of Israel, remember My favor that I have bestowed upon you and that I preferred you over the worlds.} [Quran 2:47]
Allaah The Almighty took covenant from them by means of their prophets that if the last Prophet is sent, they should believe in and follow him. Allaah The Almighty Says (what means): {And [recall, O People of the Scripture], when Allaah took the covenant of the prophets, [saying], "Whatever I give you of the Book and wisdom and then there comes to you a messenger confirming what is with you, you [must] believe in him and support him."} [Quran 3:81]
The wisdom behind sending most of the prophets to the children of Israel is their intense mischief, disobedience and rebellion. Hence, they always were in need for reformation. A corrupt society needs much greater effort from the callers to Allaah and reformers. By the same token, the society needs many doctors and physicians if physical and psychological diseases are widespread in it.
Allaah Knows best.