The preacher this morning read from Ephesians 6 and Paul’s expression in 6:16 struck me relative to the current discussion about works and salvation. There is no question whether believers will do good works or whether those good works are evidence of justification and fruit from a tree renewed by grace, as it were. As he read the passage I thought to myself, since some want to speak of the “efficacy of good works” in salvation (with the understanding that salvation is a broader concept including justification and sanctification) I wondered whether it would have been plausible for Paul to substitute “good works” for faith. Scripture says:
Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, and, as shoes for your feet, having put on the readiness given by the gospel of peace. In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; and take the helmet of salvation, and the sword of the Spirit, which is the word of God, praying at all times in the Spirit, with all prayer and supplication (Eph 6:13–18a).
Paul uses a military metaphor, in which he invokes a series of images, to describe the Christian life, the struggle with sin—mortification (putting to death the old man) and vivification (the making alive of the new man). Truth is a battle belt. On top of the belt used to hold up one’s trousers is a heavier belt to carry equipment. In the ancient world a soldier would have carried his sword there. Today a soldier carries a great deal of equipment, including his sidearm, on his belt. It is essential. He dare not leave the camp without it. The breastplate was the ancient equivalent of body armor. For the purposes of this discussion it doesn’t really matter whether the righteousness in view is intrinsic (sanctification) or extrinsic (Christ’s righteousness imputed)—although the latter seems more likely—there is no mention of good works yet. The Good News of peace with God (accomplished for us by Christ), which strengthens the likelihood that the righteousness mentioned above is justification, is what prepares us for battle. Again, our good works are not mentioned. The shield is faith, i.e., knowledge, assent, and trust in Christ, his finished work for us, and his promises.
The Christian’s shield in spiritual warfare is not his good works. It would not be possible to substitute “good works” for faith. They are not interchangeable. Faith looks to and rests in another, Christ. Good works are the fruit of that faith and evidence of its reality but they do not protect us from the assault of the Devil because our good works are always broken, always stained, always imperfect. In the hour of trial they cannot sustain or protect us. That’s why Paul says that it is faith that extinguishes the darts (the lies, the accusations, the temptations) thrown by the Evil One. Faith has an object: Christ. Faith is as good as its object. That’s why it is a shield. Good works have no such object.
We know that Paul is thinking about salvation because he says so. He nears completion of the Christian’s preparation for spiritual warfare by turning to the helmet. No soldier goes into battle with his head exposed. Even those soldiers who might not hear a helmet wear something, even if its only a boonie hat, to provide some camouflage or protection from the sun. Salvation is something conferred upon God’s people. Paul does not connect good works to it but he does connect the gospel and faith to salvation. Righteousness, of course, is mentioned but good works are not.
Finally, Scripture and prayer are the last two weapons of spiritual warfare. The Evil One is a liar and the father of lies. His first move is always to deny or twist God’s Word. “Has God really said?” He twisted the Scriptures in tempting Christ. The Second Adam faced the same Liar who confronted the First Adam. In contrast, the Last Adam defeated the Evil One by adhering to God’s powerful, truthful Word. The Second Adam prayed, for himself and for us, who he represented in his suffering, active obedience. Having been redeemed, having been saved by his grace, we too pray and through that instrument God the Spirit operates to strengthen our faith and resolve, even in the midst of dark times.
Since we obviously cannot substitute good works for faith in this passage we are left to try to imagine how others might begin to think this way. Perhaps it is due in part to an approach to justification and sanctification that sees faith in a quite limited role. For them, faith seems to be something like the starter or the ignition on a motor vehicle. We turn the key until the starter catches and the motor turns over and the engine roars to life. If we keep turning the ignition there is that awful grinding noise that reminds us to stop turning the key. The starter motor has done its job and it’s finished. The engine is running now. Is faith really like that starter motor or ignition If this passage is to guide us then we may not think of faith that way. Faith is just as active in sanctification and in salvation as it is in justification. We should not, we may not think of faith as something that performs only a narrow, technical role in justification such that when its job is completed it is put away lest it be damaged. Faith continues to be instrumental in the Christian life. This is why Paul says in Galatians 2:20,
the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.
Paul did not live his Christian life by works. He lived it by true faith. He did not regard faith as something to be used once and put away. Faith continues to be the instrument through which the justified are mystically, vitally, existentially united to Christ and it, not good works, is the shield that defeats the lies and accusations of the Evil One. This is why I’ve been arguing that faith alone is the instrument of salvation. We are being saved, i.e., believers have been justified by grace alone, through faith alone, in Christ alone and we live our Christian life, in union with the risen Christ, by faith. Having been delivered from the judgment we are now in the process of being delivered from the effects of sin, a process that will not be completed in this lifetime, by grace alone, through faith alone. God’s gracious sanctification of his people will produce good works and fruit, for which we praise God but those effects are not faith but its evidence.