Battling Sin, Christian Living

Fighting the Good Fight: How to Live the Christian Life

living the Christian life the fight of faith boxers

The men at Firm Foundation are currently working our way through a study on the classic “Mortification of Sin” by English puritan John Owen. For all intents and purposes, “Mortification” is a series of expositions on Romans 8.13 that amounts to a deep, intensely-practical dive into the theology of that one verse. The concept of the Christian life as a war is inherent to “Mortification” (which itself means ‘killing’ or ‘putting to death’) because it is inherent to the apostle’s command in the verse.

If the Christian life is a war, how are we to battle? If it’s a struggle, how are we to fight? And where is the line between my fighting and the power of God in my life? Historically, most of American Christianity has answered that question like this: ‘You can’t. You have to yield yourself to Jesus and let him live through you. Let go and let God.’ As a new believer who was struggling with sin, not only was that answer frustrating for me, but it made no sense. ‘Ok…so how do I do that?’ is what I desperately wondered.

As well-intended (and common) as that answer might be, it is thoroughly unbiblical—which is precisely why it’s so unhelpful. The reality, as John Owen points out in “Mortification,” is that living the Christian life is a struggle which requires the believer’s effort. He writes:

God has designed the task of mortification so as to keep it still an act of our obedience. The Holy Spirit works in us and upon us…upon our understandings, wills, consciences, and affections… He works in us and with us, not against us or without us, so that his assistance is an encouragement which facilitates the work of mortification rather than an occasion for neglecting it” (mod. for smoother reading).

In other words, to borrow Andy Naselli’s terminology, salvation is monergistic, which means that God works alone to save us and to bring us from spiritual death to spiritual life (Eph. 2.1-10). The Christian life, however, is synergistic, which means that we are to work out our salvation as co-laborers with God, who has equipped us for the task by his grace at work within us (Php. 2.12-13).

“The Holy Spirit works in us and upon us… He works in us and with us, not against us or without us.” –John Owen

Because of its deep roots in Keswick theology (see Naselli), most of American Christianity has that equation backwards: ‘God doesn’t force me against my will; while he holds out the rope, I can grab it and I must grab it if I’m going to be saved.’ To be fair to those who believe this way, they are affirming human responsibility and not salvation by works—but they are nevertheless affirming synergism when it comes to salvation: God has his part, and I have mine. But when it comes to sanctification, they remove human responsibility entirely and plant their flag on monergism: ‘You can’t do it, God has to do it through you; so yield to the Spirit, let go, and let God.’ This is exactly the opposite of the Bible’s picture of the relationship between God’s grace and human responsibility.

A Lesson from Israel’s Conquest of the Promised Land

During those early years of my salvation, mystified by my sin and struggling to make sense of what to do about it, I had a conversation with a close friend who made two very insightful statements that have continued to stick with me to this day. The first thing he said was that, when we are correctly living the Christian life, it is going to feel like we are doing it. The second thing he said was this: “The Christian life is guaranteed, but it’s not automatic.”

I had been reading through Deuteronomy and Joshua at that time, and his statements immediately brought to mind something I had repeatedly noticed God saying to Israel as they were preparing to enter the land: “See, I have given you this land. Go in and take possession of the land that the LORD swore He would give to your fathers—to Abraham, Isaac and Jacob—and to their descendants after them” (Dt. 1.8).


Let’s consider this for a moment. God had promised—promised, which means guaranteed and certain to do—to give the land of Palestine to Israel, a promise we see repeated continually early on in the Old Testament (Gen. 12.7, 15.18, 28.13, Ex. 23.13, Dt. 11.24). So the land was as good as theirs; it was a done deal.

But notice the means that God had appointed for the fulfillment of this promise: “Go in and take possession of the land…” (Dt. 1.8a). In other words, it was through Israel’s fighting that God intended to give the land to them. Israel was to take up their swords, march into Palestine, and drive out all the nations that were dwelling in it at that time (which, in part, they did, and which Joshua records for us), and this was how God intended to make the land their possession.

As Israel engaged in battle, what do you think were some of the things they experienced? Undoubtedly the things that are common to warfare, like fatigue, hunger, fear, injury, the real swinging of a real sword, the actual exertion of their own real energy, the actual taking of actual lives, etc. And as the men of Israel fought by the real exertion of their own energy, they were personally going to experience a very real war, and you better believe they were going to feel it. We may not know many the particulars of those battles, but we know for certain that there was no doubt in the minds of those men that they were participating in a real, authentic war, where real strength and courage were needed and real lives were lost.

In other words, it felt like they were doing it. And it felt like that because that’s what was happening.

“Notice the means that God appointed for the fulfillment of his promise: “Go in and take possession of the land…” It was through Israel’s fighting. Israel was to take up their swords, march into Palestine, and drive out the nations. This is how God intended to make the land their possession.”

God’s Fighting in Israel’s Fighting

For a moment, let’s consider the supernatural element of which Israel was reminded constantly as they prepared to enter the promised. They weren’t charged with comprehending it, but they were charged with believing it. We see it implied in Deuteronomy 1.8, but stated explicitly in passages like this:

When you go to war against your enemies and see horses and chariots and an army greater than yours, do not be afraid of them, because the LORD your God, who brought you up out of Egypt, will be with you… For the LORD your God is the one who goes with you to fight for you against your enemies to give you victory (Dt. 20.1, 4, emphasis added).

That supernatural element was the promised presence of God himself in the midst of the battle. And what God meant by ‘being with you’ was not merely that he would be in the general vicinity to offer moral support, to cheer them on from the sideline while they fought for their lives. No, his promise was that he would be supernaturally at work in them and through them as they fought: “For the LORD your God is the one who goes with you to fight for you against your enemies”—to what end?—“to give you victory.” The end-goal of God’s presence was to work victory for them—to ensure victory for them according to his promise—by working in them and through them.

And it is precisely in this picture that we see the great mystery of the Christian life: God laboring through the labor of his people to bring about their victory.

Fighting = Faith, Not Fighting = Unbelief

What becomes clear from the very beginning is that God never had any intention of fulfill his promise to give the land to Israel apart from their fighting. He never had the least intention of delivering the land to a passive, inactive, un-warring people. Not because they were inactive per se, as if God only helps those who help themselves, but because A) his ordained means was to give them the land through them and not apart from them, and B) their failure to fight was in reality a failure to believe that God would be supernaturally at work in their fighting to bring about victory. We see this as plain as day in, for example, the account of the 12 spies (Dt. 1.19-32).

But in those instances when Israel did fight in light of the promise of the supernatural presence of God in them and through them, what was the result?

“I brought you to the land of the Amorites who lived east of the Jordan. They fought against you, but I gave them into your hands. I destroyed them from before you, and you took possession of their land… Then you crossed the Jordan and came to Jericho. The citizens of Jericho fought against you, as did also the Amorites, Perizzites, Canaanites, Hittites, Girgashites, Hivites and Jebusites, but I gave them into your hands. I sent the hornet ahead of you, which drove them out before you—also the two Amorite kings. You did not do it with your own sword and bow” (Jos. 24.8-12, emphasis added).

The result, of course, was victory, just as God had promised. Clearly Israel’s victory was not automatic, but it was guaranteed. All they needed to do was pick up their swords, get to work, and fight.

We Have to Live the Christian Life

God promised to give the land to Israel. And his means of fulfilling that promise was Israel picking up their swords and taking the land from the nations. Or, to put it in John Owen’s words, ‘God designed the promise of the land so as to keep it still an act of Israel’s obedience. He worked in them and with them, not against them or without them.’

“God designed the promise of the land so as to keep it still an act of Israel’s obedience. He worked in them and with them, not against them or without them.”

And here is the lesson for us: We have to live the Christian life. Christ-like perfection is a promise—so much so that Paul can speak about it in the past tense as if it’s already done (Rom. 8.29-30). But while it’s guaranteed, it’s not automatic.

The Christian life is a battle, and we are to be engaged in it. The Christian life is a struggle, and we need to be working at it. The Christian life is a fight, and we need to be fighting. Like Lazarus, Jesus has brought us to life and enabled us to walk, and he commands us to rise up and do so. And so, as a matter of obedience, we need to employ the life that he has breathed into our lungs and legs.

And where, exactly, are we to be working? Answer: in the things that God has given us to do.

church leaders Pastor Tony

About the Author

Tony de la Riva is an elder and pastor at Firm Foundation Bible Church and is earning an MDiv at The Master’s Seminary. He is originally from Fresno County, CA, and he and his wife Beki have been married since 2007 and have four children. More from Tony ⟶

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