These verses show some do not repent as they see no sin in their life. Some repent and find rest. Those that come unto the Lord must repent. Sorrowing over sins is in a sense repentance but for the repentance of concern there must be a turning unto the Lord. John Baptist turned some away from baptism unless they brought forth fruits meet for repentance.
Salvation requires a particular repentance.
One can be most miserable because of their sins without the additional grace of salvation. Judas ended up one very unhappy person. Esau was rejected from inheriting the blessing for he found no place of repentance though he sought it carefully with tears. Turning to God includes acceptance of all God's total will for one's life. With repentance there is a returning to God.