Mark Twain was very unhappy with himself for various reasons. He was very unhappy with America of this time. He thought it was terrible we had no anti-lynching laws, and he was also a feminist, and he was also very concerned with anti-Semitism. He was a good man, but he was hard on himself.
The things that have always been important: to be a good man, to try to live my life the way God would have me, to turn it over to Him that His will might be worked in my life, to do my work without looking back, to give it all I've got, and to take pride in my work as an honest performer.
My god is all gods in one. When I see a beautiful sunset, I worship the god of Nature; when I see a hidden action brought to light, I worship the god of Truth; when I see a bad man punished and a good man go free, I worship the god of Justice; when I see a penitent forgiven, I worship the god of Mercy.