If you say you'll do something, do it. It doesn't bring a good person out of you if you say you'll do something and never realize it. You won't show people the good person you could be. The kind of person who is trustworthy and the kind of person who will earn people's respect simply for carrying out with things like you said. Seriously, how hard could it be? Not too hard, that's for sure. If you're not going to follow through, make sure you have a valid and concice answer.
“No one saves us but ourselves. No one can and no one may. We ourselves must walk the path.” - Siddhartha Gautama