“"Can the Ethiopian change his skin Or the leopard his spots? Then you also can do good Who are accustomed to doing evil..”
Jeremiah 13:23 NAS
Note here that the Ethiopian cannot change his skin, nor can leopard changes spots. So what the Lord is telling us is that the depraved man cannot change his nature and become a force of good. Of course depraved men can occasionally do good things but they are still depraved men. Like the leopard and the Ethiopian the depraved man can never change himself, but there is still hope because the Holy Spirit has been given authority to regenerate souls and heart of that depraved man. It will not be the work of the man to make himself righteous, it will be the work of God to make a man righteous.
Matthew 19:24-28 (NAS)
24 "Again I say to you, it is easier for a camel to go through the eye of a needle, than for a rich man to enter the kingdom of God." 25 When the disciples heard this, they were very astonished and said, "Then who can be saved?" 26 And looking at them Jesus said to them,
"With people this is impossible, but with God all things are possible."27 Then Peter said to Him, "Behold, we have left everything and followed You; what then will there be for us?" 28 And Jesus said to them, "Truly I say to you, that you who have followed Me, in the
regeneration when the Son of Man will sit on His glorious throne, you also shall sit upon twelve thrones, judging the twelve tribes of Israel.