Yes, I believe that Lust (Using definitions 2&3 at the link) is sinful, particularly when mentally "wallowed in". Likewise, Gluttony, Greed, Sloth, Wrath, Envy, and most particularly Pride are sinful.
I'm not clear on what, if any, credence Jewish people give to anything in the Holy Gospel According to St. Matthew. I gather it's not much, though ...
45 posted on 08/22/2011 12:27:50 PM PDT by ArrogantBustard
(Western Civilization is Aborting, Buggering, and Contracepting itself out of existence.)