Lex finally realized why the feeling of power when he was about to take his oath felt so familiar. It was similar to the voice that invited him for a new job that he rejected. A worker for the Inn can't be working jobs for other people.
He felt it again now, acknowledging his oath - selfish though it may be - for he had truly overcome great adversity to stick to it. An oath that was easy to fulfil was not really impressive. It was only overcoming the impossible - or at the very least overcoming what was very hard - that would prompt the birth of a Paladin's power. For example, fighting off demons with a weak and frail mortal body.
That's what David Paladin had to do to attain his powers. Lord only knew what he did after getting his powers.
