Sin: Save Yourself First?

There is a wise maxim about not taking refuge in absolutes, and one of the reasons to follow this occurred to me today.
I seem to see a lot of people getting very worked up about things they regard as sin. Gay marriage seems to be the current fashion but there is no shortage of other issues it seems.
Next time someone appears on your TV telling you something they don’t approve of is sinful, stop and have a good look at that person. Two of the “Seven Deadly Sins” are Sloth and Gluttony. These are things that knowingly hurt other people either by action or omission, so qualify as genuine sins by most reasonable definitions. Does this moral crusader look like they eat way more than they actually need? Do they look like they could change this behaviour, but can’t be bothered? There is probably a big chunk of self-pride thrown in there too, which is another sin we are told. If they are so passionate against sin, why are they so tolerant of their own?
Why are you listening to protestations about another’s alleged sinning from someone who makes no efforts to deal with their own actual sinful behaviour? It is something to think about when you have a spare minute.
If gay is wrong should nuns be allowed to be fat?