One of the joys of reading widely is in finding interesting connections between things that might otherwise seem to be unrelated. Let me explain.

I recently read through R.C. Sproul’s book What Is Reformed Theology? Actually, I’ve recently read through almost all of R.C. Sproul’s books and have noted that he has several recurring emphases. One of these is the importance of a right understanding of God’s work of preservation. Of course this emphasis makes sense when you know that Sproul is a long-time teacher and defender of Reformed doctrine.

Sproul’s concern with understanding the doctrine of the Perseverance of the Saints is not purely a theological one; it is not simply that he wants to have his theology right. His concern is practical. “There is clearly a link between our assurance and our sanctification,” he says. “The person who lacks assurance of salvation is vulnerable to a myriad of threats to his personal growth. The confident Christian, certain of his salvation, is free from the paralyzing fear that can inhibit personal growth. Without assurance we are assailed by doubt and uncertainty with respect to God’s promises, which serve as an anchor for our souls.”

What Sproul wants people to see is that assurance of salvation, a doctrine which flows out of God’s act of preservation (Sproul says rightly that the doctrines may be distinguished from one another, but never separated), is critical to spiritual growth. Those who lack assurance that they are saved often become bogged down by concern for their salvation. They have trouble growing in their faith because they cannot see past the uncertainty about their own spiritual condition. And this makes perfect sense, right? It is difficult to grow in the deeper things if we are still wrestling with the very basics. This is why every Christian should seek assurance of his salvation.

Now let’s turn for a moment from R.C. Sproul to Nancy Pearcey (and if you want to know what binds the two authors together, it would probably be a shared love for Francis Schaeffer). In her book Saving Leonardo, Pearcey has a chapter on “Sex, Lies and Secularism.” She writes about how sex is perceived in our secular culture and says this: “A video put out by Children’s Television Workshop defines sexual relations as simply ‘something done by two adults to give each other pleasure.’ No hint that sexuality has any moral or social significance. No suggestion that it has a richer purpose than sheer sensual gratification, such as bonding husband and wife together to create a safe haven for raising children.” Secularists miss the bigger, better purpose for sex and reduce it to an exchange of physical services, a mere commodity.

When people make sex into something so small, they miss that it has many big purposes, one of which is as a unique means of binding a husband to a wife and a wife to a husband. When a husband and wife are enjoying the sexual relationship, when they are bound together in this unique way, there is a stability to their relationship. And within the stability of the relationship of father to mother, children can thrive, knowing that they are raised in the safe haven of a committed family. And this is one of the reasons God gave us sex—to create the stability our families need.

Do you see how these two things relate to one another? Here is Sproul telling us that we can best grow as Christians within the context of God’s perseverance and here is Pearcey telling us that we can best raise families within the context of a stable, committed family. In both cases, God has given us the structure we need to thrive. And in both cases Satan will do whatever he can to destroy those structures. He will steal the assurance Christians have that they are truly saved and will watch as they wither, as they find that they cannot grow in the faith. And he will destroy families or disrupt the sexual relationship so he can undermine the stability in which children can grow and thrive.

So I suppose at the end of it all I’m left seeing anew the importance of the sexual relationship not just to a husband and wife but to their family (though that family will, hopefully, be unaware of the details, of course!) and the importance of pursuing and finding assurance of salvation. In both cases, God seeks our good and Satan seeks our destruction.