The Virtue of the Pagans

I've been reading this book by Matthias Sheben right now on grace. He talks about how the grace of God is infinitely, but maybe not infinitely. And that's but I guess I don't understand how it works in relation to our virtue. Because obviously, there are noble pagans who are far more virtuous than us. Is he responsible for their growth in virtue? Yeah. To love God above all things in our neighbor as ourselves gives a kind of transcendent horizon to the whole virtuous life and it brings the whole virtuousLife together.