G-d has plenty of angels who can fill that role. Calev spells it out for us. That is the criterion for favor from G-d. Try your best, and don't rebel. Back to guilt.
Physical pain is very useful and beneficial.
Without pain we would not know that we have touched a flame, or dropped something heavy on our foot, etc. Pain alerts us to stop whatever it is that we are doing which is inflicting damage on us. When a person is whole emotionally, doing things which we know are wrong causes us guilt. The pain we call guilt lets us know that there is something we ought to stop doing. There is guilt which is founded in morals and conscience.