A clean confession combined with a promise never to commit the sin again, when offered before one who has the right to receive it, is the purest type of repentance.
I have come to the conclusion that whether or not a person is a religious believer does not matter. Far more important is that they be a good human being.
A religion old or new, that stressed the magnificence of the universe as revealed by modern science, might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths. Sooner or later such a religion will emerge.