Trained instincts—that's how fighter pilots can react immediately to rapidly changing situations as they operate $27 million war machines. When a threat aircraft is closing in, there's no time for pilots to reason through what to do. They have to rely on instinct—but not just natural instinct. They need instincts shaped deep within them through years of regiment. The countless little decisions they make in the cockpit are automatic, but that doesn't mean they're involuntary. The pilot voluntarily trained for them, and in the cockpit he reaps the instinctive benefits of that training.
This is a good illustration of how unintentional sin works. Can we be guilty for sinful responses that seem to erupt in us automatically? Can we really consider sin voluntary if it is not consciously chosen?
Scripture's view of human experience is complex enough to answer yes. Scripture speaks of involuntary sins as including three characteristics: they are (1) from ignorance of God's will and therefore (2) not deliberately chosen as hostile acts against God, yet (3) they are disobedience nonetheless. Leviticus 5:17 describes unintentional sin as "doing any of the things that by the Lord's commandments ought not to be done, though he did not know it." Peter told his law-celebrating Jewish brothers they "killed the Author of life" because they "acted in ignorance" (Acts 3:15, 17). Paul told his idol-loving Greek audience their long artistic history was actually "the times of ignorance" that God had overlooked (Acts 17:30).
The Jews killed Jesus. The Greeks crafted idols. Both of these actions were instinctive expressions of hearts not conditioned by God's revealed Word, but by differing (yet equally sinful) sets of beliefs and values. The Jews believed in a legalistic god of their own making and valued their cultural version of righteousness; the Greeks believed in their human-crafted gods and valued the beauty of their own imaginings. Their actions simply expressed these deeper structures of ignorance. The Jews did not intend the killing of Jesus to be a hostile act against God, and the Greeks did not intend their pursuit of earthly pleasure to be direct rebellion against Him. But they were nonetheless.
So it is with us. Our responses flow from somewhere—from the deeper realities of the hearts we're stewards of. We are stewards of the deeper realities just as much as we are of the surface expressions. So, we can sin without deliberate choice because we are always acting intuitively out of hearts conditioned by inherited sin. Jesus gave us the general paradigm for this when He told us that "out of the abundance of the heart the mouth speaks" (Matt. 12:34).
Like the fighter pilot's hours of training, our hearts are under a regimen that gives shape to our intuitive responses—a regimen of beliefs and values that don't align with Scripture, drilled into us through what we put in our heads, what we receive as wisdom from other sources, what we accept as normal from culture. All of these shape our unintentional sin.
Think of the way sins such as partiality (James 2:1), jealousy (3:14), or harshness (4:2) function in real life. Rarely do people intentionally decide to show partiality. Yet, they're instinctively drawn to a beautiful person who comes into the room. Why? Because of their established perception of what is attractive. Jealousy is the automatic impulse that arises when my deep value for a certain thing meets my hidden assumption of personal entitlement to it. Harshness is the result of the quiet desires of my heart smacking up against a person I perceive as withholding those desires from me.
These sins tend not to have a moment of decisive action; they sort of emanate from our vitality. And in case that's not bad enough, these basic unintentional sins can emanate in more complex forms, too: partiality can express itself as racism, jealousy as workaholism, harshness as manipulation.
Sins of ignorance can only be remedied with knowledge. Far from being an excuse for sin, ignorance is the thing that keeps us in it. We become aware of unintentional sins—and more than that, are given the ability to do something about them—only by an external word from God. In Leviticus, this is a man "realizing his guilt" by knowing the will of God as laid down in Scripture (5:17). Peter's solution to the Jews' ignorant murder of Jesus is to refer them to Scripture's prophecies about Him (Acts 3:18). Paul speaks to the Greeks' idolatry about the one God not made of gold or silver (17:29). Only then, with this new awareness of truth, can they possibly take the proper action against their unintentional sin: "Repent, therefore, and turn back, that your sins may be blotted out" (3:19).
If we're using it rightly, Scripture is that uncomfortable knife—a sword, in fact—that cuts deep (Heb. 4:12). But as deeply as it cuts, it is for the purpose of God's sculpting that glorious, instinctive design He put in us when He saved us. When a person believes God's Word, he is given a mind characterized by the righteousness of Christ, out of which flows new understanding (1 Cor. 2:14–16). The same design that makes human beings able to sin instinctively is now used for good. When people come to faith in Christ, they receive His righteousness—not just as a declaration of right standing before God (justification), but also as a living power that reshapes their core beliefs and values, and therefore the instinctive responses that flow from them (sanctification). Their automatic responses are characterized by greater righteousness. Trained instincts—but now under a new regimen.