The other day an acquaintance was with me when my 13-month-old daughter made her first attempt at walking. My friend and I both threw our arms in the air and raised our voices the obligatory two octaves as we told her she was "SOOOO BIG!" The baby responded by putting her own chubby arms up, which meant that we had to do it again, which promoted her to do it again, and, long story short, my cardio for the day was playing the "SO BIG!" game about 78 times.

After the baby moved on to the more interesting activity of eating food items on the kitchen floor (what I call "sweeping"), I remarked with a wistful sigh that I was happy that the newborn phase was over. I'm not a natural baby person, I explained to my friend, and so it felt like I'd been waiting for eons for this baby to get a little older.

"So you guys are done, then?" she said.

It took me a second to process her statement, since for a split second I wasn't sure how her question was related to what I'd previously said. While I fumbled for a way to concisely explain my answer to questions about family size, she clarified her statement with a comment I've heard many times before. "You don't want to spend the rest of your life changing diapers, do you?" she asked.

I understand why she'd ask. When I was younger, I would have posed the same question. All the work! The sacrifices! The lack of freedom! Aren't you just itching to be finished with all that? 24-year-old me would have wanted to know.

One of the most shocking truths I discovered when I converted to Christianity was that autonomy is not the path to happiness. I always thought that the secret to a fantastic life was to optimize on getting as much autonomy as possible, so that I could do whatever pleased me, whenever I felt like doing it. I was surprised when I found out that that kind of life left me amused but not deeply happy, and I was shocked when I discovered that the only source of real happiness -- of joy -- is God. And you only need to glance at a crucifix to be reminded that God is the God of self-sacrifice.

Through Christianity, I discovered the secret formula for the fantastic life I always wanted: Being other-focused. We each need to make regular time to recharge our own batteries -- and, as I've said before, I believe that modern mothers need to be especially careful about this. But the overall purpose of life is to serve, and the closer you get to God, the more he’s going to set you up with opportunities for some serious self-sacrificial service.

That's why, as lazy as I am, I just shrugged when my friend asked if I'm anxious to be done changing diapers. Even if I could wave a magic wand and give myself NFP superpowers to control our fertility with 100% accuracy for the rest of my fertile years, I don't think I'd do it. There are a lot of reasons why this is the case, but on a purely practical and selfish level, I don't think I would have any less work to do. From what I've seen of the Christian life so far, I presume that as soon as my last kid is out of diapers God will simply send more opportunities for challenging, personal service my way. Maybe our parents will become ill and need our assistance. Maybe a relative will need to move in with us. Maybe we'll be called to take in foster children or volunteer with the homeless. Perhaps our oldest children will start having kids around the time our youngest is finally potty trained, and then a whole new cycle of diaper changing will begin again!

"Changing diapers" has become the ultimate symbol of the sort of intimate service that leads to a lack of autonomy -- which is probably why our culture has such a deep distaste for it. It's also why I’m ambivalent about it: The Christian life is always all about self-sacrificial service. So maybe it won't literally involve Huggies and baby wipes, but, yeah, if I am to make the most of my time here on earth, I do assume that I'll spend the rest of my life changing diapers.