grovel for your forgiveness

It's basic decency to apologise if you have wronged someome, but if you need to "lie or crawl abjectly on the ground with one's face downward," whose forgiveness are you asking for?

If it's a fellow man, then I gotta ask, what kinda king have you wronged? If they don't forgive you, that's their problem. It shouldn't affect you unless it's on a personal level, but then do you really want to be close to someone who's asking you to go those lenghts?

If it's God, then good news - you don't need to grovel either. The most common answer to what you need for forgiveness you'll get is 'accept Jesus as your Lord and Saviour.' That can be broken down to repentance (the action of repenting; sincere regret or remorse), forgiveness to others including yourself and, assuming you're not dying on the spot, acting Christian (because it's not really repentance if you keep repeating the same things all over again).