One of the brothers, Jagāi, was astonished to see this behavior of Nityānanda Prabhu, and he at once fell down at His feet and asked Him to pardon his sinful brother. When Mādhāi again attempted to hurt Nityānanda Prabhu, Jagāi stopped him and implored him to fall down at His feet. In the meantime the news of Nityānanda's injury reached the Lord, who at once hurried to the spot in a fiery and angry mood. The Lord immediately invoked His Sudarśana cakra (the Lord's ultimate weapon, shaped like a wheel) to kill the sinners, but Nityānanda Prabhu reminded Him of His mission. The mission of the Lord was to deliver the hopelessly fallen souls of Kali-yuga, and the brothers Jagāi and Mādhāi were typical examples of these fallen souls. Ninety percent of the population of this age resembles these brothers, despite high birth and mundane respectability. According to the verdict of the revealed scriptures, the total population of the world in this age will be of the lowest śūdra quality, or even lower. It should be noted that Śrī Caitanya Mahāprabhu never acknowledged the stereotyped caste system by birthright; rather, He strictly followed the verdict of the śāstras in the matter of one's svarūpa, or real identity.
When the Lord was invoking His Sudarśana cakra and Śrīla Nityānanda Prabhu was imploring Him to forgive the two brothers, both the brothers fell down at the lotus feet of the Lord and begged His pardon for their gross behavior. The Lord was also asked by Nityānanda Prabhu to accept these repenting souls, and the Lord agreed to accept them on one condition, that they henceforward completely give up all their sinful activities and habits of debauchery, both the brothers agreed and promised to give up all their sinful habits, and the kind Lord accepted them and did not again refer to their past misdeeds.
This is the specific kindness of Lord Caitanya. In this age no one can say that he is free from sin. It is impossible for anyone to say this. But Lord Caitanya accepts all kinds of sinful persons on the one condition that they promise not to indulge in sinful habits after being spiritually initiated by the bona fide spiritual master.