Two Types of Sin

Sin can be both willful and non-willful.

It is willful sin which brings death, non-willful brings correction.

Rom 6:16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?

1. Sin unto death
2. Obedience unto righteousness

Sin unto death = disobedience unto unrighteousness.

Therefore...

Jas 4:17 Therefore to him that knoweth to do good, and doeth it not, to him it is sin.

Thus...

Gen 2:16 And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat:
Gen 2:17 But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.

Rom 6:23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.

Eze 18:20 The soul that sinneth, it shall die. The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.

1Jn 5:12 He that hath the Son hath life; and he that hath not the Son of God hath not life.

1Jn 5:16 If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.
1Jn 5:17 All unrighteousness is sin: and there is a sin not unto death.
1Jn 5:18 We know that whosoever is born of God sinneth not; but he that is begotten of God keepeth himself, and that wicked one toucheth him not.

Two kinds of sin. One is rebellion, the other is falling short in ignorance. It is only rebellion which cuts one off from God (spiritual death).

Hence the context of the warning...

Heb 10:26 For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
Heb 10:27 But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
Heb 10:28 He that despised Moses' law died without mercy under two or three witnesses:
Heb 10:29 Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?

Num 15:30 But the soul that doeth ought presumptuously, whether he be born in the land, or a stranger, the same reproacheth the LORD; and that soul shall be cut off from among his people.
Num 15:31 Because he hath despised the word of the LORD, and hath broken his commandment, that soul shall utterly be cut off; his iniquity shall be upon him.
Num 15:32 And while the children of Israel were in the wilderness, they found a man that gathered sticks upon the sabbath day.
Num 15:33 And they that found him gathering sticks brought him unto Moses and Aaron, and unto all the congregation.
Num 15:34 And they put him in ward, because it was not declared what should be done to him.
Num 15:35 And the LORD said unto Moses, The man shall be surely put to death: all the congregation shall stone him with stones without the camp.
Num 15:36 And all the congregation brought him without the camp, and stoned him with stones, and he died; as the LORD commanded Moses.

 Now here is one of the most beautiful passages in the entire Bible.

Rom 8:1  There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
Rom 8:2  For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
Rom 8:3  For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
Rom 8:4  That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.

It is the Spirit of life in Jesus Christ which sets us free from the law of sin and death. Why is that? It is because when we walk according to the Spirit by a faith that works by love we are no longer engaged in that which brings our ruin. What a wonderful salvation.