The thing about stress, is that it never stays just that "I dont like this" feeling. It doesnt stop at not feeling comfortable with a given situation.
Stress is a building block for so many other things that are more destructive feelings, which is where the sin lies.
How many times have you said, or been the victim of someone who says hurtful or does hurtful things then says "I was just really stressed out"?
What about the times that you yell at your children, talk hurtfully to your husband, feel bitter toward a task God gave you to do, are paralyzed into inaction by your feeling overwhelmed. Stress simply opens us up to other feelings that can lead us to a sinful place.
Take for example my favorite example of a lack of forks :). Every night at dinner the husband gets frustrated because he cant find a fork, that leads to his expressing his frustration, which leads me to being frustrated that I cant ever remember to buy any, making me ask the question "why cant I pull it together?", which leads to me feeling negative towards myself ..inadequate, and overwhelmed with ALL the things like that need doing in the house!
Or, when you open your closet and its full of clothes that dont fit. You get frustrated that they dont fit, you feel fat and out of control ....you all know where that one leads.
Stress left unchecked can lead to a whole range of negative emotions, which can lead to a whole list of possible sinful actions towards the people we love, and the God we serve.
So, just buy the forks, get rid of the grown clothes, get control of the laundry, just GO to the gym, get over what so-and-so said, ..it stops stress before it starts in those areas. That eliminates the possibility that that stress will cause you to stumble the next time!
And always remember, to "Stay alert! Watch out for your great enemy, the devil. He prowls around like a roaring lion, looking for someone to devour" I Peter 5:8