Being holy. . . does not mean being perfect but being whole; it does not mean being exceptionally religious or being religious at all; it means being liberated from religiosity and religious pietism of any sort; it does not mean being morally better, it meas being exemplary; it does not mean being godly, but rather being truly human.
It's not so much that the old friend is a better friend. It's just that you know the person better, and you know they don't really care if you're acting like a poor, grovelling idiot. They know you would do the same for them.