If you are hell-bent on something, you have set your mind on it and you will not stop — even when other people do not like the plan, and even when it is unwise. The feeling is strong and a little wild. People say it in informal talk; it sounds rough because of hell, so you would not put it in a careful school essay. The usual way is hell-bent on plus an -ing verb: hell-bent on winning, hell-bent on leaving. It can also work like an adverb, especially in older, colourful English (he drove hell-bent down the hill), but hell-bent on… is the pattern you will hear most. Though actually, this is not about religion; hell here only means “with all the force a person can summon.”