Who in their right mind is willing to pay over three hundred dollars and spend thousands of hours hurting their bodies to finish what they started? Those who are willing to do Ironman races is who. I have done six Ironman 70.3 over the last 2 years. For me to finish those Ironman I had to train at least 3 hours 6 days a week to finish better then my last race. I can't remember one of those races where I didn't want to quite. One race I found myself puking during the swim portion of the race. Trust me that was no fun. I totally wanted to quit but I didn't.
It's ok to want to quit. Jesus wanted to quit before he finished his purpose. Look at what the author Matthew wrote in the book of Matthew chapter 26 "My Father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will." Those are Jesus' word sound a lot like someone that wants to quit but he goes on to say your will be done not mine. See its ok to want to quit but don't. Quitting lasts forever the pain that you are going through will be gone at some point. So keep going. You know the results of quitting.
Here is the trick I think, when we get to that point in life where we want to quit on our marriages, jobs, family and working out is to remember why you started. What was it about that person you fell in love with or why did you sign up for that race. See passion gets us started but discipline keeps us going. Most of us are really good at starting things but lack the discipline to tell ourselves to keep going for it.
How to finish:
Write down why you started. Why did change jobs? Was if to spend more time with your family? Why did you want to get into shape? Was it to live longer so you could see your grandkids? Why did you go back to school? Was it to get a better paying job so you can travel?
What ever the reason is when you want to quit think about why you started and if the reason is still better then the reason why you want to give up then keep going. Finish what you started. More people started in every race I have been in then finished because it's so easy to quit.