Regeneration: the problem
nWe are by nature unfit due to our sin:
nThe LORD looks down from heaven on the sons of men to see if there are any who understand, any who seek God there is none who does good, not even one (Psalm 14:2-3)
nCan the Ethiopian change his skin or the leopard its spots?  Neither can you do good who are accustomed to do evil (Jer 13:23)