Socrates: “So by our line of reasoning, Meno, it appears that being good is a quality that comes to people, when it does, by gift of god.”
– Plato, Meno (Adam Beresford’s translation)

It’s amazing how Socrates can come up with this conclusion, knowing that he was living in the context of Greek polytheism. We can indeed only be good when God puts to death our sinful nature and gives us a new life, in union with the death and resurrection of Christ.

P. S.: for a more comprehensive explanation on union with Christ, please refer to this link.