On what bases does God hold humans morally responsible, i.e., culpable, for their actions? This question is at the heart of salvation. God, who is just, must be just in His justification of those who trust in Christ (Rom. 3:26) and in His condemnation of those who do not believe (John 3:18).
I see in Scripture three grounds upon which God holds men responsible: 1) capacity, 2) knowledge, and 3) intent. Of these three, intent is the most frequently mentioned and most obvious.
Determination of culpability on the
basis of intention is evident from Num. 35:16-34 and Deut. 19:4-6. A
man who "without knowledge" (bivli da'at) or unintentionally (bishgagah) slays his neighbor “does not
deserve to die” (cf. Josh. 20:3). If the one who commits unintentional manslaughter is killed by the "avenger of blood," God regards it as the shedding of innocent blood (Deut. 19:10). While intentional manslaughter receives the death penalty, involuntary manslaughter receives no direct punishment for the perpetrator is not held guilty.
It is noteworthy that no sacrifice is prescribed
for the man who commits unintentional manslaughter, implying that God
does not regard it as sin. Interestingly,
a lack of intent is also paired with a lack of motivation: “he did not
hate him previously” (Deut. 4:42; 19:4, 6; Josh. 20:5). On the other
hand, a desire to harm or malice toward another is grounds for culpability when an act leads to harm (Num. 35:20-21).
Intent is also a key basis for the distinction between the sin offering (Lev. 4) and the guilt offering (Lev. 5). The sin offering was offered when sin committed unintentionally became known.
In Num. 9:6-8 certain men were not able to keep the Passover at the appointed time because they were ceremonially unclean. They approach Moses to ask for a ruling, a statement of divine justice, regarding their case. Yahweh reveals to Moses that such persons are not guilty of sin and need not be cut off from Israel (Num. 9:10-12). Rather, an alternative time for celebrating the Passover is provided. In contrast, those who are able to celebrate Passover and choose not to do so were to be cut off from Israel (Num. 9:13; cf. 2 Chron. 30).
It is noteworthy that the issue in Num. 9 is not inherent capacity, but a lack of ability due to being disqualified for ceremonial reasons. If incapacity that is not inherent removes culpability, how much more would incapacity that is inherent remove culpability?
The conclusion from Numbers 9 that capacity is necessary for culpability is supported by our innate sense that real capacity is a necessary condition for personal responsibility. Requiring blind persons to pass a sight test in order to qualify for assistance with their blindness is necessarily unjust and thus immoral because they have no capacity to meet the requirement.
Knowledge as a factor in determining culpability runs two ways. First, one may commit an act that is sinful without being aware that one is doing the act (Num. 35:23). This kind of action is described as being done "without knowledge" (Deut. 4:42; 19:2; Josh. 20:3, 5) and is covered above under intent.
Second one may commit an act that is sinful without knowledge that it is sinful. In such a case the lack of knowledge regarding the requirement renders one not culpable for the wrong done. The clearest texts that address this factor in culpability are Rom. 2:12 and Rom. 5:13.
In Rom. 2:12 Paul asserts that those who do not have the law are not judged by the law, despite the fact that they have broken the law. They are not morally responsible for their sin, because they were not aware of the law.
In Rom. 5:13, Paul notes that although sin was present in the world prior to the giving of the Mosaic Law, that sin against the law was not imputed to their account.
Given two assumptions--the immutability of the divine nature and that Scripture's revelation of the nature of justice reflects accurately divine justice, I conclude that God will not hold persons culpable for a) what they are not capable of doing, b) what they do not know to do, or c) what they do not intend to do.
On the ground of divine justice alone, any conclusion that God holds fallen humanity morally responsible for what it is incapable of doing implicitly renders God unjust. Since Scripture is clear that God does hold all of fallen humanity responsible (Rom. 1:18-22; 2:10-12; Acts 17:30) and that no fallen man is capable on his own to do any good thing or to seek after God (Rom. 3:10-18), one must conclude that God acts to grant capacity to all humanity to respond to the knowledge He provides them.