God only deals with individuals. Psalms 33:14-15 states this. Though marriage is two people becoming one, that does not apply to what God is accomplishing in each of us. Philippians 1:6 applies to individuals. The armor of God in Ephesians 6:13-17 lists qualities of an individual. Though more than one person can apply them to life, each person must do it personally.
This means that we cannot blame anyone else for our own lack of maturity which includes our spouse. Our own spiritual maturity is not dependent on what our spouse chooses to do or not do.