"Yes, but when I married him, he had quit drinking and was committing to church and other positive changes in his life. I didn't realize how bad the alcohol problem was and I was young and naive and in love and I thought that church friends and positive influences would be enough to keep us on that growth path." I was wrong, but I didn't have a crystal ball and I couldn't predict that his negative patterns would get worse over time and that he'd pretty much turn his back on church, etc.
I guess... well, wishful thinking is different from planning. You can't build a castle on sand, right?
I've fallen into this trap of thinking so many times. Someone recently told me that life will provide us with the same lesson over and over and over again until we finally get it through our heads. That felt true to me. Holding on to the dream, long after that dream should have dissolved, long after the point where my mental and emotional health is at risk, is one of mine. I'm still working on it.