Why do people want to quit?

I remember last year, going through this same stuff from people in our core team. This year, it's from the 2nd tier of members - people who began attending regularly last year, and are consistent leaders this year. Something's not going right, and I hear "I just want to quit" from them!

My heart is not made of stone! When I hear that they want to quit, it makes my heart drop! I get hurt. It tells me, you don't like us. You're not willing to stick through the rough times with us. This is not easy - starting a church, or maintaining a 2 yr old church - and it won't be easy maintaining a 10 yr old church! There will always be another challenge around the corner that seems insurmountable. But, we just say - I've seen the insurmountable mounted and toppled. We can do this (through Christ). That's why, don't tell me you're going to quit! You give me heart failure when you do! I like you. I don't want to see you leave. I don't want to leave. God's the only one that's ever there for us. He never quits on us. I guess I quit on Him all the time. :o(