I do think it's a poor idea to try to change your spouse. The only control we are meant to have in this life is self-control. However, I think we inevitably DO change our spouses, hopefully in positive ways through our constant support and positive example.
One story from our early marriage:
My husband and I are both religious and we were both in the habit praying before bed. I noticed that he prayed on his knees before getting in bed. I was accustomed to praying in a more perfunctory way after my head hit the pillow.
He never said a word to me about it, just continued to pray the way he always had. It made me restless, though, seeing him on his knees in apparent devotion and reflection. I itched to do the same. At first I tried it when he wasn't watching (like when I went to bed first). I found it to be a much better approach for me that drew me closer to God and helped me be more focused and alert in my prayers, and before long he and I were both on our knees every night. It's been that way ever since. He changed the way I pray, which in turn changed me... but without saying a word. I'm sure something similar has played out in many ways I'm unaware of as well as the things I've observed.
Some things, of course, never change. He still rinses dishes and doesn't load them in the dishwasher. I still shake my head at it. :) We each do things the other one doesn't love, and I'm sure our imperfections have had their effects on the other one as well.
Certainly our relationship has deepened my joys and at times exposed me to deep hurt as well. I think every relationship brings those possibilities and intense emotions shape us as well.
Here's a more recent picture of us: