My parents both identify as Christians, Mom more so than Dad, but neither has been to church in years. I have attended independently since high school. While my father and younger brother were away, my mother confided in me that she would like to find a local church to attend, but that my father is hesitant to go because he "distrusts the institution of the church." As a church-goer myself, I would love to see my mother plugged into a church community. I told her that she is perfectly able to go out and find a church home with or without my father since he refuses to take her. She refused to attend church without him, explaining that part of the reason her own parents divorced after a forty year marriage was that her mother regularly attended church without her father. It hurts me that my father, being a Christian, won't accompany his wife to church, and I am concerned that her spiritual needs aren't being met. I would take her myself, but I live several hours away and am rarely home. I know that my parent's marriage is none of my business, but what advice can I offer my mother regarding this situation?
You are quite correct that if your mother wanted to attend church services, there is nothing stopping her. She merely hides from her choice by putting the blame on your dad.
"If anyone comes to Me and does not hate his father and mother, wife and children, brothers and sisters, yes, and his own life also, he cannot be My disciple. And whoever does not bear his cross and come after Me cannot be My disciple" (Luke 14:26-27).
Until she loves God the most in her life, she will continue to put worldly things and worldly people first. You can't directly solve this problem because it is an issue in your mother's heart. You can only encourage her to make the right decision. Also set a good example. "But seek first his kingdom and his righteousness, and all these things will be given to you as well" (Matthew 6:33). Don't skip services because of family events but instead invite your family to join you.
While both your parents call themselves Christian and live basically moral lives, neither are living the life of a Christian. See: Does a person have to attend church? One cannot legitimately call Jesus Lord while not accepting his rule. "Why do you call me, 'Lord, Lord,' and do not do what I say?" (Luke 6:46).