Ironically, the first key to changing your spouse is to stop trying to do it by yourself. This sounds counter intuitive but the reality is that no human being has the capacity to change another human being. We change because we want to and it is God that puts the ‘want to’ inside of us.
Philippians 2:13 explains it this way. ‘God is working in you to help you want to do and be able to do what pleases him’. Ask God to work in your spouse. Often we try to work on our spouse rather than letting God work in our spouse.
You must decide whether what you want is change or adjustment. Adjustment is a response to external pressure. Change is a response to internal conviction. Adjustment is temporary; change is permanent.
This is vividly illustrated by people who try to pressure a person to change their behaviour as a condition of marriage. They lay down ultimatums like ‘If you change XYZ I will marry you’.
The difficulty with adjusting under external pressure is that as soon as the external pressure is removed we revert back to our natural self. Once the marriage is achieved the person has no further incentive to keep up the behaviour adjustment.
By all means communicate where you would like to see changes but if what you want is a real heart change in your spouse then you have to hand them over to God and trust God to engineer the change from the inside out.
The less you try in your own power, the more effective it is. Pressure does not change people permanently, conviction does. Only God has the capacity to truly change another human being