The "Supposed To's" of Marriage and God

How much of a role does God really play in relationships? I have been rolling this thought over in my mind, trying to really process it and understand it. All during my high school years, I was taught "God needs to be the center of your relationship" but that idea was never really explained to me. What does that really mean? What does that look like? I tried all kinds of things, going to the same church, praying together, discussing the Bible, etc. But each individual act never seemed like enough. Just because we prayed together didn't mean God was the true center of our relationship.
However, I say all this, and I could say that (on a good day) God is the center of my marriage. We focus on God's will for us individually and as a couple, as well as (try to) pray together and read the Bible together.
Lately, though, those practices seem to have fallen by the wayside. We're busy, we're tired, we'd rather do something else... the excuses seem to pile up and God gets forgotten. But then so does the health and spiritual well-being of our marriage. I can see it change how we interact with one another and other people, as well as how we view our marriage one day to the next. There seems to be an absence, a void and negativity are present. We fight more, we overreact, we get defensive... makes for a lousy time, that's for sure.
But what does reading the Bible do? Could we still feel a deeper connection if we read a novel together? What is that spiritual aspect that is so important? We are busy people, and we make the time to spend with friends, work, church, etc., but not for reading the Bible together, or praying or doing any sort of devotional or study. How do we balance that, especially when Michael doesn't get home until 10pm and we're both too tired? Are we "supposed" to pray even though the act of closing our eyes to pray would make us fall asleep? Or are we "supposed" to get up early together to do something, with the same problem of falling asleep? How do busy people do it? Or are we "supposed" to set aside the time that we aren't working and are together, and spend a few minutes reading the Bible, praying, etc. But when Michael is working 4-5 nights a week, it gets difficult to even find the time to do that. But if something is a priority, we'll make it happen. So we'll see what we figure out!
God values relationships, so it makes sense that by taking the time to value our relationship with Him, He'll bless us and make our relationship a bit easier/closer. I know that praying and reading your Bible isn't the miracle cure to marriage hardships, but by growing closer together through reading the Bible sure puts you on the right path for it. When our relationship becomes nothing but fighting and resentment, something definitely needs to change. So here's to change and trying to refocus our relationship back on the one who brought us together. It wont be easy, but it will be good!