Old Testament law distinguished between sins of ignorance, or sin unintentionally (Lev 4:2, 13-14; Num 15:24-29), and premeditated sins (“sin presumptuously” or with a high hand, Num. 15:30-31). Sins committed in ignorance incur guilt (Lev 4:13,22,27); however, the sacrificial system provided atonement for such sin (Lev 4; 5:5-6). In contrast, “high-handed” or “presumptuous” sin is an affront to the Lord punishable by exclusion from the people of God. The Law provided no ritual cleansing for such sin (Num 15:30-31).
Common images for sins of ignorance include error (Lev 5:18), straying (Ps 119:10), and stumbling (Job 4:4). By extension these images can be applied to any sin. Thus Prov 19:27 warns against willful “erring” from words of divine counsel.
The NT speaks of past ignorance that God excuses. Such was the ignorance of those Jews who participated in crucifying Jesus (Acts 3:17; 13:27). Of Paul who persecuted Christians (1 Tim 1:13), and of Gentiles who did not recognize the true God (Acts 17:30). Though God overlooks such past ignorance, He requires repentance (Acts 3:19; 17:30). Obedience characterizes lives of the converted just as ignorance desires characterizes those without Christ (1 Pet 1:14). The NT speaks of deliberate ignorance as well as “excusable” ignorance. Most often deliberate ignorance involves the stubborn the acknowledge nature’s witness to the powerful existence of God (Rom 1:18-21; Eph 4:18; 2 Pet 3:5).