In Numbers 15, Moses describes two manners in which a man might depart from walking in God’s commandments. The first way in 15:22-29 is often called sinning inadvertently, unintentionally, or ignorantly. English translations commonly stress the unawareness or obliviousness of the one who sins. The second way is 15:30-31 is called sinning willfully or presumptuously. English translations commonly stress the awareness or purposefulness of the one who sins.
The consequential distinction is a matter of whether or not the sin can be forgiven. Aside from the added concerns for restitution and so forth depending on the sort of sin, the sin can be forgiven if it is committed in the former way but not in the latter way. The former way can be addressed by the mercy of purification offerings and such. The latter is to be denied such mercies, and the sinner is to be cut off from the people of God.
I would challenge the notion that the dividing line between the two manners is a matter of awareness or purposefulness. I think that is an error brought about in the translation process and the drift of meaning in English. I would propose that the dividing line is one of weakness versus defiance.
In Numbers 15:22-29, the sort of sin (usually called ignorant or inadvertent) is described using a word which indicates going astray or off course, wandering, or meandering. And in Numbers 15:30-31, the sort of sin (usually called willful or presumptuous) is described using a phrase meaning “with an uplifted hand” or as “sin of the high hand” as some say.
I think the stone of stumbling in our understanding here is the meaning of the language of knowledge and ignorance. The Epistle to the Hebrews picks up on the Levitical context and speaks of the weakness of the people as well as “the sins of the people committed in ignorance” (9:7) and “sinning willfully after receiving the knowledge of the truth” (10:26). The author to the Hebrews recognizes this distinction of sins in Numbers 15 and applies it to the forgiveness of sin by the blood of Christ under the New Covenant.
In Hebrews 9:7, the phrase “sins committed in ignorance” is just a single word meaning ignorance or lacking knowledge. So it speaks of offerings made for the ignorance of the people. It’s related to the word for knowledge in Hebrews 10:26. Both in the Hebrew and Greek in Scripture, knowledge is generally about more than a bare awareness of facts. It carries connotations of familiarity, preference, intimacy, affirmation, approval, etc.
The people of God have not received a bare factual awareness of the truth. Eternal life is not a bare factual awareness of the one true God and Jesus Christ whom he sent. A man does not have a bare factual awareness of his wife and then begets a child. God does not have a bare factual awareness of Israel his chosen so as to set them apart from the other nations. All these instances of knowing demonstrate a familiarity, preference, intimacy, affirmation, approval, etc.
I submit that this is the sense in which we should take “sins committed in ignorance” in Scripture. This certainly covers the matter of any done in obliviousness. And this is more consistent with the notions of our going astray, wandering off course, or meandering in our struggle with weakness. These are the things toward which a faithful high priest has mercy and compassion.
In contrast, we should take presumptuous or willful sins in Scripture to mean those that are committed in defiance with hearty approval and delight. The words used to describe this connote the sense of firm deliberateness and resolved resistance. And the imagery of an uplifted hand, i.e. shaking a clenched fist raised in the air, confirms this. This manner of sinning will receive no mercy or forgiveness, in part because it doesn’t want mercy or forgiveness. This is a manner of sinning that is committed to the love of sin.
And as an added note for pastoral care, be aware that sins of defiance can become and be reckoned as sins of meandering if the sinner comes to his senses and repents. This is how it is treated under the Old Covenant and the New Covenant. So, if you’re ever worrying in angst if you have committed a sin of defiance, you may well have. But your present worry and anxiousness over it may well reassure you that it’s now a sin of meandering toward which Christ the faithful High Priest has mercy and compassion.