I stand in front of a huge mountain. It is formidable. I might fail. I am likely to fail. But I cannot give up. I need to have faith even though I haven't much right now to be quite honest.
Keeping promises is hard. It requires us to do things we don't want to do. But keep those promises you must do. Otherwise, do not make them in the first place. But since you have made them, you must keep them, especially if it would benefit all those involved including yourself.